Aamber Pegasus prototype

Thu, 3 Jan 2013 16:15:26 +0900

It’s been 3 years since I last updated this blog, so it’s about time I added something new.

I was sent these images of what looks to be an Aamber Pegasus prototype with a newly designed sheet metal case.

Not too much information available on this, but it certainly looks like it could use a clean. It also has extra ROMs directly hard wired into the system.

The Chronicles of Amber by Rodger Zelazny

Mon, 18 Oct 2010 21:11:32 +0900

I found out something very interesting today. I had often wondered where the name ‘Aamber’ came from. Seems that one of the three partners who started Technosys back in 1980 was a huge Roger Zelazney fan, and in particular liked his series of books ‘The Chronicles of Amber’. The double ‘A’ was added to ensure that the name appeared first in any alphabetical listing, no doubt having something to do with one upping Apple Inc.

Videos of all the games

Mon, 9 Aug 2010 09:19:14 +0900

I finally finished making short videos of all existing Aamber Pegasus games. I used the save uncompressed AVI option in M.E.S.S. but unfortunately this produces videos that play considerably slower than 100% emulation speed, and much slower than on a real Aamber Pegasus. This is most notable for games like Pegapong and Hangman 2 which never played very fast in the first place.

You can see all the videos here

Pascal 1.0 manual uploaded

Mon, 19 Jul 2010 21:11:39 +0900

Thanks to Chris Diphoorn we now have a PDF of the Pascal 1.0 manual. This manual has been missing from our collection for a long time, and finding it is a huge relief.
Thanks Chris.

24 and counting...

Wed, 7 Jul 2010 08:57:34 +0900

I just realized that we now have 24 unique program, games and languages. You can see them all here

This is fantastic news considering when I started this site that I just had 2, Forth and Mon 1.0.

Even better news is that there are still some dedicated programers writing new programs for the Pegasus including Chess, Smurf Olympics and a machine code version of Character Generator. Please stay tuned.

Chess for Pegasus

Sun, 4 Jul 2010 17:11:45 +0900

Paul Sowden has revived one of his old games, chess, and is presently attempting to update it with new graphics and a few bugs fixes. I’m certainly looking forward to playing the final game.

A simple guide to using the M.E.S.S emulator

Sun, 4 Jul 2010 12:59:36 +0900

I have received many enquiries on how to use Pegasus emulation in M.E.S.S, so I thought I’d write a simple guide.

You can find the write-up here

Technosys & Aamber Pegasus Wiki updated

Thu, 27 May 2010 22:18:49 +0900

Someone had already set up ‘Aamber Pegasus’ and ‘Technosys Research Lab’ Wikipedia page, but I thought the original postings were a little sparse on information. I decided to add more to the write-ups and included some photos and logos. This was my first adventure into Wikipedia land, and I found it interesting to see how it all works.

The wiki page can be found here:
http://en.wikipedia.org/wiki/Aamber_Pegasus

8K EPROM 24-Pin and 28-Pin Differences

Wed, 19 May 2010 06:22:42 +0900

John’s simple guide to differences between 24 pin and 28 pin EPROMs. This document is available from the server.

Analysis of Pegasus memory decoder

Wed, 19 May 2010 06:15:09 +0900

As part of the Pegasus 2010 clone initiative, John Turner has documented the Aamber Pegasus memory decoder in detail. This complete document is available from the server.

Hangman 2 ported to Pegasus

Sat, 15 May 2010 13:54:26 +0900

I know the Pegasus already has a version of Hangman, so I’m not actually sure why I did this port...Anyway, I did, and as always it’s available from my server.

Golf ported to Pegasus

Fri, 14 May 2010 21:12:33 +0900

Now with the upgraded RAM in emulation, more complex games can be written and ported. Here is the latest port from me...GOLF.

MESS emulation upgraded with 24k RAM

Fri, 14 May 2010 21:10:50 +0900

Robbbert has upgraded the Aamber Pegasus emulation in MESS to now include 24k of RAM.

TAPE2ROM Loader

Thu, 13 May 2010 07:10:16 +0900

John Turner has written some 6809 code to load cassette based binaries into ROM. This will allow any cassette based program, which has been converted to a binary file, to be loaded onto an EPROM and run from any ROM space (even if the original program only runs from a specific address). The code resides at the beginning of the binary file. John has tested it with the Pegasus Tank cassette game, which is loaded into address B000-BFFF.

A loader prompt will show in the menu. Pressing ‘L’ will relocate the program from ROM into the appropriate RAM address, and from there the actual program will appear in the menu, and in the case of Tank, pressing ‘T’ will then launch the game.

In other news, I have fixed a small error in the original Tank graphics which now takes the Tank version to 1.2. The file is called ‘TANK12_T2R.bin’ and can be downloaded from my FTP server.

Hangman archived

Tue, 11 May 2010 22:53:25 +0900

Included in the Galaxy Wars dump is also a little game called Hangman. I used to love this game when I was 11 years old.

The looooooong wait is finally over...

Tue, 11 May 2010 22:43:26 +0900

Well, I just realized I’ve been trying to track down the Galaxy Wars EPROM dump for over 5 years!!! I just wanted to thank all the people I’ve bugged, harassed and generally annoyed during this time, but I especially wanted to thank Paul Carter, Jo Carter, Paul Sowden, John Turner and Robbbert for their help in finally getting this archived. A true team effort.

Maybe now is a good time to rest...

As always, this game is available from the server.

New RAM/ROM board designed

Tue, 11 May 2010 06:17:27 +0900

In a lead up to the Pegasus clone, the Pegasus 2010, John Turner has designed a new RAM/ROM board for the Pegasus. The Eagle files are available from my FTP site in the ‘Projects’ folder.

What follows is an overview of John’s design:

The Aamber Pegasus Memory Expander, Version 1.0 (hereafter referred to as simply "The Memory Expander"), is a device intended to expand the Memory Capabilities of the Technosys Research Laboratories, Ltd. Aamber Pegasus 6809 Personal Computer. The Pegasus came factory equipped with only 4K of RAM, 512 bytes of which serve as Video RAM, and a 4K Monitor ROM. The onboard RAM is mapped at: $B000 - $BFFF, whilst the Monitor ROM is mapped at: $F000 - $FFFF. The Monitor ROM is designated ROM 1 (or EPROM Socket 1) and is always mapped at $F000 - $FFFF. There are two additional ROM sockets onboard, designated ROM 2 and ROM 3 (or EPROM Socket 2 and 3). ROM 2 is normally mapped at $1000 - $1FFF and ROM 3 is normally mapped at $0000 - $0FFF. There is, however, an alternate addressing scheme available for both ROM 2 and 3. The default Jumpers map these two ROMs at the aforementioned addresses. By changing the Jumpers, either or both of these ROMs may be mapped to an alternate address range. ROM 2 may be remapped to $D000 - $DFFF. ROM 3 may be remapped to $C000 - $CFFF. The original design of the Pegasus allowed for a maximum expansion to a total of 48K of RAM. This was accomplished by leaving the ROM 2 and ROM 3 at their default address ranges of $1000 - $1FFF and $0000 - $0FFF, respectively. Expansion RAM of 44K was then added to $2000 - $AFFF and $C000 - $DFFF, bringing the total to 48K. Later, some ROMs were devised to occupy the RAM addresses such as $2000 - $2FFF. ROMs containing PIC (Position Independent Code) could be executed properly regardless of which socket that they occupied. The Memory Expander has been designed to provide SIX EPROM Sockets, mapped at all of the standard Pegasus ROM addresses plus the RAM address range of$2000 - $2FFF. Further, each socket is made to accept any standard 28-pin EPROM - anything from a 2764 (8K x 8) to a 27512 (64K x 8). Each socket is set up to be "banked" in 4K "banks", thus any single EPROM, regardless of size, still only occupies it's respective 4K area in the memory map. The active "bank" of the EPROM is set using a 4-position DIP switch, with the switches being set to the 4-bit binary equivalent of the desired 4K "bank". Each socket supports up to 16 "banks" of 4K via the 4-position DIP switch. Obviously, a 2764 would only provide two "banks" while a 27512 would provide the full complement of 16 "banks". Additionally, any of the six EPROMs may be disabled (and thus removed from the memory map). This is accomplished via a six position DIP switch, with each of the six switches representing one of the six EPROMs. The Memory Expander has been designed such that if any EPROM is disabled, it is automatically replaced by a 4K chunk of RAM. This feature allows a total of 56K of RAM to exist in the memory map along with the Monitor ROM, or 60K of RAM if the Monitor ROM is disabled. It is very likely that the 56K setup will be the largest practical RAM setup, since there needs to be some sort of software, such as the Monitor, in charge of the CPU for it to be of any use. Please note that the Memory Expander plugs into the 6809 CPU socket on the Pegasus motherboard, and the 6809 CPU then plugs into the Memory Expander. Also, all three ROMs (or however many happen to be installed in the Pegasus) MUST BE REMOVED FROM THE MOTHERBOARD. The equivalent of these ROMs Will now exist on the Memory Expander (at least after you have obtained a proper set and have then proceeded to install them). Also note that the ROM images of the Pegasus ROMs that the Memory Expander requires are the "TRANSLATED" ROMs - the "RAW" ROMs will not work with the Memory Expander. These "TRANSLATED" images can be generated by the "Rewire4K.exe" application for the Microsoft Windows(tm) Operating System. Please see the Memory Expander documentation for details regarding where to download this freely available piece of must-have software.

Pegasus 2010

Sun, 9 May 2010 12:07:15 +0900

Interesting news. I have been in contact with a very enthusiastic retro computing and electronics hobbyist who has been discussing the idea (and has started drawing schematics) for a remake of the Pegasus, called the Pegasus 2010.

Possible specs include:
- Switch to run the CPU at a higher speed
- VGA output
- 48k standard (original only had 4k standard)
- Built in ‘EPROM expander’ (to run all existing languages at the flip of a switch)

If there is enough interest, boards may be professionally produced. Please email me if interested.

Stay tuned...

Your move sexy

Thu, 6 May 2010 17:48:53 +0900

I had previously mentioned about the
YES BOSS ? prompt that VERY occasionally appears on the Pegasus menu screen. Today I also found this one. Your move sexy!

Hurkle ported to Pegasus

Wed, 5 May 2010 19:25:31 +0900

Now that cut and paste is working in the MESS emulator, I can now make quick ports of some Creative Computing games for XBasic. Memory is a little limited so the programs can’t be too long otherwise I get an error #80.

As usual these games are uploaded to the server.

Handy ‘cut and paste’ emulator tips

Wed, 5 May 2010 12:37:59 +0900

Even though ‘cut and paste’ in the MESS emulator has been fixed, some quirks still exist that make it tricky to port programs to the Pegasus.

The biggest issue I have come across is that the emulated Pegasus can’t keep up with the speed that the pasted characters are being received. This often causes dropped or missing characters which makes it very difficult to easily easily convert programs. This issue is most obvious when the Pegasus’s cursor is at the bottom of the screen and the screen is scrolling as the code is being pasted.

Even though ‘cut and paste’ in the MESS emulator has been fixed, some quirks still exist that make it tricky to port programs to the Pegasus.

The biggest issue I have come across is that the emulated Pegasus can’t keep up with the speed that the pasted characters are being received. This often causes dropped or missing characters which makes it very difficult to easily easily convert programs. This issue is most obvious when the Pegasus’s cursor is at the bottom of the screen and the screen is scrolling as the code is being pasted.

One fix is to add a buffer into the code you are copying and pasting. Another is to send a CLS (Clear Screen) command which repositions the cursor at the top of the screen. A combination of these two techniques seems to work 99% of the time.

So here is what I do:
I open the code in Microsoft word, and from there I do a ‘find and replace’.

I search for all ‘Returns’ (written as ^p)

^p

and replace them with

^p^p^p CLS^p^p
(Thats a few ‘Returns’ followed by a few ‘Spaces’, then a ‘Clear Screen’ command, then finally a few more ‘Returns’)

The resulting listing may look a little ugly but it works pretty well for pasting code into the emulator. Some experimentation may be needed and sometimes I randomly throw in a few extra spaces for time buffering, just for good luck. This buffering is especially needed when some of the pasted lines are long, and the Pegasus needs a little more time to process them.

I’ve already ported new Pegasus versions of Lunar Lander, Nicoma and HiLo, and you can download these from the server.

If you have a better solution to ‘cut and paste’, please let me know.

Good luck, and lets see some new Pegasus programs!

2532 to 2732 and visa versa adaptor.

Wed, 5 May 2010 11:10:57 +0900

John Robert has given permission to host a bunch of his upcoming Aamber Pegasus projects. His first one is relatively simple, a 2532 to 2732, or conversely, 2732 to 2532 EPROM adaptor.
Eagle files for this adaptor are available from my FTP server under: Aamber Pegasus/Documents/Others.

Lunar Lander ported to Pegasus

Tue, 4 May 2010 13:55:13 +0900

Hi Lo ported to Pegasus

Mon, 3 May 2010 20:50:43 +0900

Nicoma ported to Pegasus

Mon, 3 May 2010 20:43:39 +0900

New ‘Surround’ game written in Forth

Sat, 1 May 2010 19:07:28 +0900

The legendary ‘Surround’ game written in Forth and converted to the Pegasus by Chris Smith.

Your task is to control the man (astrix) who runs around the screen trying to avoid the randomly-produced blocks which appear next to him. You must avoid having to run into a block for as long as possible and the computer keeps count of how many times you have moved.

Chris says that there are more improvements to this game coming soon. In the meantime you can download version 1.0 from my FTP site.

Instructions:

To start type GO
4 up  3 down  8 left  9 right

XBasic now working in emulation

Sat, 1 May 2010 17:40:10 +0900

Robbbert reshuffled the ROM address allocations around a little, and removed one of the virtual cartridge ports today. This mimics a real Pegasus machine more closely. After he did this the three ROM XBasic set now works.

The new ROM addresses are:

first one: 0000
2nd one: 1000
3rd one: 2000

Aamber Pegasus MESS emulation is out

Wed, 28 Apr 2010 15:35:00 +0900

The new MESS build is out today, It’s a little buggy and crashes often on my machine, but the final Pegasus build is included, and now the Pegasus graphics work great. See the screen capture showing the game ‘Tank’.

Pegasus in Emulation FINISHED

Tue, 27 Apr 2010 21:18:21 +0900

Today is my birthday, and there is no better present to get than a finished Aamber Pegasus emulator.

It took Robbbert just three days to complete everything...and I mean EVERYTHING. Now how crazy fast is that.

Basic, Forth, Pascal, Invaders, Word, and MAD ROMs all work. These images are loaded in like game cartridges into 4 available ‘cart’ slots.

Invaders and Tanks wav files both load into Monitor using the emulated cassette.

Snakes, Star Trek, Char Save, Char Gen and Pegapong all load and run in Basic.

The only thing I haven’t been able to get working is the 3 ROM set for XBasic, but then again, I haven’t been able to get them working on my real Pegasus yet either. Anyway, three cheers for Robbert. Awesome job.

You can download the latest, and daily builds of MESS from here:

http://bobz38.free.fr/mess_autobuild/index.php

As always you can download all the files needed for MESS from my FTP site. Please check it out.

Pegasus in Emulation 3

Mon, 26 Apr 2010 19:42:14 +0900

Much progress has been made today.
Ironically the first program Robbbert actually got working was my Pegapong game. Robbbert was also able to re-save the Pegapong game from the emulator to a .wav file, which I could then load up on my real Pegasus. Amazing!

Some of the captures above show some video corruption as they were taken at different stages during the video fix. This corruption now been resolved.

Still no luck getting either Invaders or Tanks to load yet.

Some highlights from todays efforts include:

- Fixed display of the number "9", confirmed on real hardware, mistake in Motorola datasheet
- Added reverse video
- Pegapong game works
- Keyboard is complete
- Added cassette and cartslots
- PIA, IRQ code added. Fixed typo in video code

Keyboard matrix mapped

Mon, 26 Apr 2010 13:29:10 +0900

Between Robbbert and I, we mapped out the Pegasus keyboard matrix for use in the MESS emulation. It turned out to be much harder than I first thought, taking about 3+ hours to decipher. A total pain in the ascii.

Pegasus in Emulation 2

Mon, 26 Apr 2010 12:43:58 +0900

More updates from Robbbert.
Cassette emulation running. Save and load now working.

Pegasus in Emulation

Sun, 25 Apr 2010 16:41:58 +0900

I recently became a member of ‘the bee board’, a forum dedicated to the Australian made computer, the Microbee.

Part of the board’s registration process was to write a few paragraphs about yourself. Naturally I wrote about the Pegasus. A few days later I received a reply to my post from Robbbert (yes, thats three b’s). Having had a look at most of the files on my server, he said that he wouldn’t mind having a go at emulating the Pegasus using MESS. Naturally I was skeptical, however I was exited at the prospect and offered to help in any way possible.

Skip forward 2 days, and I receive an email from Robbbert telling me that he has a bare bones emulation up and running. A few back and forth emails later, he even had the Pegasus welcome screen displaying (see image above). Amazing!!!!

In his own words, he still has much to do, the least of which is to map the keyboard matrix and emulate it. Without that there is no way to see if any of the emulated ROMs work.

Looking forward to seeing what Robbbert can accomplish next.

Galaxy Wars and Hangman on their way...

Wed, 14 Apr 2010 21:02:05 +0900

Much thanks to Paul Sowden and Jo and Paul Carter for organizing between themselves the copying of the Galaxy Wars and Hangman EPROM.

Paul Sowden has not yet been able to get the EPROM working on his modified Pegasus system, but has done a preliminary memory dump of the ROM. Paul believes the code probably resides in the wrong memory space for it to function on his machine, and some tinkering may be needed to get it working...

Dual multi PROMs

Sat, 3 Apr 2010 09:37:50 +0900

Using two of Jim Brain’s 2364 adaptors wired together in parallel to a 16 position rotary switch. I now have a simple Multi EPROM system that allows me to switch between 16 different images in pairs, which includes dual EPROM languages like Pascal and Forth. The trick is to burn the multiple language binaries (Sets A and B) into the same banks on both EPROMs. It took me about 2 hours to build everything, and I tested it this morning and it seems to work perfectly.

MON 2.3 is now archived

Fri, 2 Apr 2010 15:10:43 +0900

Much thanks to Gary Hammond for backing up his MONITOR 2.3 EPROM. Another ROM can now be struck of our MIA list.

When checking the MON 2.3 hex file in a hex editor, the code seems to differ drastically from MON 2.3a.

On a side note. Gary also sent me some pictures of his Pegasus, and it too is completely different from any Pegasus I’ve seen before. It has a solid steel case, with a typographic ‘Aamber Pegasus 6809’ logo written in the funky 70’s Pegasus Invaders typeface. The internals differ slightly with a never seen before Multi EPROM board (containing RAM), and with two extra sockets hard wired to the prototyping area containing XBASIC B and C. XBASIC A is placed in one of the three standard EPROM sockets. Gary’s Pegasus is pretty cool looking so I’m quite jealous. Pictures to come.

YES BOSS ?

Wed, 31 Mar 2010 12:16:40 +0900

The guys at Technosys surely had a sense of humor when they coded the Pegasus Monitor ROM. Occasionally upon reset, instead of the regular ‘Computer ready’ (with one of the later MON revisions) or ‘Select one of the above’ (with the earlier MON versions), the computer will actually display the prompt ‘YES BOSS ?’. The frequency seems totally random, but I can only estimate that it occurs on average once in every 50 resets. This time, as I was cataloging all the Pegasus software, I was able to snap off a picture.

Actually I’ve never seen it happen with Monitor 2.3a, and have only come across it when Monitor 2.2 (or earlier?) is installed.

I remember seeing this when I was a kid, and used to press the reset button repeatedly trying to get the message back. Oh the joys of youth!

PEGAPONG now at version 2.0

Thu, 25 Mar 2010 20:33:09 +0900

New title screen, some reworking of the game playing area so that there is an actual dead center, and a slight speed increase means I am now at version 2.0.

Keys for player 1: Q A Z
Keys for player 2: P L <

PEGAPONG update soon...

Wed, 24 Mar 2010 17:23:45 +0900

I worked a little bit on updating PEGAPONG today. Nothing dramatic, and it’s still a WIP. I realized it was very difficult to see where the ball was going to bounce, so I’ve put in some walls. In addition, to help make things feel more authentic, I’ve put in a net too.

Multi PROM

Tue, 16 Mar 2010 10:58:12 +0900

I had previously built this 2364 (or 23128 & 23256) to 27XXX adaptor for my Sinclair ZX81 so I could switch between multiple OS’s. However last night I realized I could also use it to run multiple OS’s on the Pegasus too. The Pegasus uses 2532 EPROMs which essentially share the same pinouts as the 2364’s, however the 2532’s have half the memory. The simple trick was to double every file I burnt to the EPROM.

Of course I am not able to run multi-ROM languages such as FORTH or Pascal (maybe with some hacking), but I was able to burn files such as Basic, MAD, Word and Invaders to a single 27256 EPROM, and now I can easily switch between them. This frees up 3x2 more sockets on the Pegasus EPROM switcher board...more than enough to install XBasic, and every other known ROM variant for the Pegasus.

I purchased this adaptor kit from Nicolas Welte:
http://freenet-homepage.de/x1541/hardware/2364-c.html

and another possible option is Jim Brain’s ROM-el:
http://www.jbrain.com/2009/08/09/rom-el-testing-complete/

Dragon = Invaders?

Sun, 14 Mar 2010 21:22:08 +0900

I can only assume that the Dragon game shown in the Pegasus price list is actually Invaders. I can’t find any reference to the game Invaders in any of the newsletter or manuals, and no one I’ve spoken to has any knowledge of a game called Dragon.

PEGAPONG 1.0b

Sat, 13 Mar 2010 22:20:27 +0900

Ok, ok...I know it’s quite pointless. I mean, really, how many people will ever get to play my newly coded version of PONG for TinyBasic...maybe just me, and that’s even sillier considering its a two person game! Regardless, I enjoyed the experience and learnt some things in the process.

This is version 1.0beta. It is a little slow, and I’m still not 100% happy with it in places. Maybe I’ll have another crack at it when I have more spare time.

The .wav file can be downloaded from the server.

Keys for player 1: Q A Z
Keys for player 2: P L <

Proof that people did use the Pegasus

Wed, 10 Mar 2010 21:11:31 +0900

Chris Smith finds someone’s loose notes on interfacing the Pegasus to a S-100 bus in a used book that he purchased called ‘The S-100 and other micro busses’.

Chris cut his teeth learning Forth on the Pegasus, so It’s Ironic that he happened upon this document. He has a page dedicated to the Forth language here:

web.mac.com/xrissmith/Forth/FORTH.HTM

For what it’s worth, these three loose sheet have been scanned and can be downloaded from the server.

Could it be true...

Wed, 10 Mar 2010 20:13:00 +0900

Could we be only days away from archiving the mythical missing Galaxy Wars EPROM?

Character weirdness on board #2856 - SOLVED

Fri, 5 Mar 2010 20:58:33 +0900

Well, it took a few emails back and forth with Alan Candy, the last owner of this board (Alan purchased it from the original owner many many years ago), but together we managed to solve the character problem. A single trace had corroded to the extent where it had broken, the fix was as easy as bridging the corroded trace with a short length of wire.

Now that the board is up and running, I have noticed something unusual, this board does not have any security restrictions like most Pegasus boards, this means it can use any EPROM from any other Pegasus machine...Nice!

The other good news is that this board seems to work well with the 12 EPROM switcher board...not surprising at they came as a set, but I wonder why it didn’t work with the other one???

Now all I need to do is figure out how and where the 3 XBASIC EPROMs install.

Character weirdness on board #2856

Wed, 3 Mar 2010 22:40:13 +0900

Having gotten board #2856 partially working (albeit with a garbled screen), I decided to try it with the invaders EPROM as I knew this program uses UDG graphics that redefined the Pegasus character set...Well, invaders worked perfectly. The graphics looked great. No problem at all.

Jumping back to the Pegasus menu screen actually retained the invader character set (my other board defaults back to the standard set) which would allow me to partially read the menu (in a kinda 1970’s funky typeface). So it would seem the the default character set is not being read on boot-up, or when returning to the menu. More trouble shooting is needed.

One other point of interest is that the display seems rock steady which makes me believe that all the jitter fixes have been done on the board.

Some success with getting board #2856 running

Wed, 3 Mar 2010 22:26:46 +0900

As I was blowing fuses every time I tried to power this board up, I decided to have a look at the hacked power area on the solder side. A bunch of extra tantilum caps, a diode and a red wire were all soldered onto and around the power area where non of these components existed on my other board. After playing around with it a bit, I decided to desolder the red wire. Surprisingly this stopped what ever short I had. Great!

I plugged in the TV and put the MON 2.2b EPROM into socket 1 and powered up again with fingers crossed...nothing, a blank screen. looking back at some photos I took of this computer before dismantling it for transport, I noticed that the MON EPROM was actually in the middle socket, and not socket 1 as in my other board. This board originally had a home-brew RAM card inserted into socket 1. So I decided to try the MON EPROM in the middle socket instead. I didn’t have much faith in this working, but on power-up I was greeted with a screen full of garbage. Looking closely I could see that the patterns corresponded to the Pegasus boot screen. Pressing ‘M’ to enter the monitor allowed me to type more garbage on the screen. A good start.

12 EPROM switcher board... some problems

Mon, 22 Feb 2010 20:13:07 +0900

I have been messing around with the 12 EPROM switcher board in my original Pegasus board #2569. This switcher board switches between EPROMs in banks of two’s.
I seem to be having some issues. Most of the programs/languages work when installed on the switcher board, with a few exceptions:

- Invaders works fine when using MON 2.2, but becomes corrupt and hangs when using MON 2.3.

- Loading Tanks or Invaders from .wav file also causes problems with MON 2.3 when the switcher board installed.

- Forth 1.3 and Forth 1.1 do not work at all. Hangs with a blank screen.

- XBASIC. This is a 3 EPROM set, and I believe the switcher board needs to be modified for them to work. I was hoping that it was already modified as XBASIC came with the board, however I have had no luck in getting XBASIC to work. Looking at the bottom of the switcher board I can see that some modification has been done, but I am unsure of what this modification does.

New EPROMs

Mon, 22 Feb 2010 20:06:33 +0900

So I recently received a batch of Pegasus EPROMs, some of which I previously had, but some are new to the archive, and some I’m not even sure what they are.

Here is a list of what’s new:

Mon 2.2
Mon 2.2b
XBasic 1.0 (three eprom set)
Invaders 1.1
Word 1.1
GD3P (no idea what this is)
UTILS (possibly some useful 6809 routines)

Updated Invaders v1.1 to v1.2

Mon, 22 Feb 2010 19:30:15 +0900

Along with my new acquisition from trademe.co.nz came some interesting EPROMs, all of which I have dumped. One EPROM contained Invaders 1.1 which I only previously had as a cassette .wav file.

After getting my Pegasus up and running again (see previous post), I noticed that Invaders 1.1 had some corrupted UDG graphics. These were most apparent on some of the UDG text. I converted the hex to binary and fixed the graphics and burnt a new EPROM. I’m calling the corrected graphic version invaders 1.2