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Compass II wanted (1129, 1139)

tschak909

Experienced Member
Joined
Mar 26, 2018
Messages
120
Location
Denton, TX USA
GRiD Compass II wanted to aid in the restoration of GRiD software development tools (it's not going to be thrown into a glass case.)

If you have one for sale, please msg me.

-Thom
 

JDat

Member
Joined
Jul 26, 2022
Messages
16
Sounds interesting. I am working on GRiD Compass emulator. We can share knowledge.
 

tschak909

Experienced Member
Joined
Mar 26, 2018
Messages
120
Location
Denton, TX USA
Here is a GRiD 2101 Hard Disk image with a complete development system on it.
 

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  • grid-hd.zip
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tschak909

Experienced Member
Joined
Mar 26, 2018
Messages
120
Location
Denton, TX USA
@JDat where is your emulator ?

(I ask, because I REALLY could use it. The 1101 emulation in MAME is good, but trying to run GRiDDevelop on just 128K of RAM just doesn't work!, and I really miss the window manager)

(as an aside, I am _really_ angry at the speculative state of the retrocomputing market, compass'es going for more than $6,000, ultimately to people who will never ever actually use them. Just ERMAGHERD! NASA ALIENS LAPTOP! ... I'm actually trying to preserve the GRiD environment while the pieces are all still here!)

-Thom
 
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JDat

Member
Joined
Jul 26, 2022
Messages
16
Emulator is still in early development stage.
Bubble and GPIB not working yet (top priority).
1101 ROM dump is running. Getting message: "Cannot boot: Storage medium error"
Video subsystem for 320x240 is working. 512x256 not tested yet.

I need some help on hardware research. Like beeping some physical pins on mainboard with multimeter because I don't own Compass (too expensive for me).
Lot of information and help comes from @usernameak who disassembled 1139 ROM.

MAME version is made by @usernameak
From time to time we are talking about Compass hardware and CCOS details on telegram chat.

Looks like your HDD image is empty or broken. No files here.
 

JDat

Member
Joined
Jul 26, 2022
Messages
16
Oops. *embarrassed* posted the wrong one. :)
Still no files. It is really weird that 10 MB image is compressed to 46 kb ZIP file. After unzipping and examine image with hex editor I see that whole hard disk contains UUU characters. Something wrong with ZIP? Can you try 7zip compression on image and or share/upload on external web page?

Also, because I am newbie and there are stupid rules, I can not upload or attach anything to post. So here are some information from my collection:

* Screenshots of old (July/August) emulator version:
* I also researched ROM dumps from NASA computer. There are dumps for U25 and U26. I found them on yahoo group backup/export. After some manipulation with split and merge there is small (256 kb) FAT12 file system image with some MS DOS test tools for GRiDcase. Mount's in my linux easly and some utils (keyboard test) run in DOSbox. Happy hacking!
Here is image NASA ROM image: https://ufile.io/cxxjuqw1

* And here is HDD image what I got from @usernameak or... Somewhere from internet.
https://ufile.io/oocy8gup
 

JDat

Member
Joined
Jul 26, 2022
Messages
16
Can anybody help with small reverse engineering on Compass/Compass II main board? Can you beep connections on main board from following ICs?
For Compass 1101:
1) U25 Intel 7220 bubble memory controller. Where goes/is connected pin 7 !DACK
2) U25 Intel 7220 bubble memory controller. Where goes/is connected pin 8 DRQ
3) U25 Intel 7220 bubble memory controller. Where goes/is connected pin 9 INT
4) U42 Intel 80130 Interrupt/timer controller. Where goes/is connected pin 31 IN1 (Sometimes called IRQ1)

For Compass II 1139 this can be pins for 8259 PIC controller, pin 19, but I am not shure.
The idea is to find out where is connected bubble memory controller's DMA request, DMA acknowledge and Interrupt request (IRQ) pins and where are connected IRQ pins on interrupt controller.
I can't do it because I don't own Compass and motherboard pictures on internet don't have good view angle and resolution to research Compass virtually via Internet.

Than you for your valuable work and information in advance.
 

tschak909

Experienced Member
Joined
Mar 26, 2018
Messages
120
Location
Denton, TX USA
Can anybody help with small reverse engineering on Compass/Compass II main board? Can you beep connections on main board from following ICs?
For Compass 1101:
1) U25 Intel 7220 bubble memory controller. Where goes/is connected pin 7 !DACK
2) U25 Intel 7220 bubble memory controller. Where goes/is connected pin 8 DRQ
3) U25 Intel 7220 bubble memory controller. Where goes/is connected pin 9 INT
4) U42 Intel 80130 Interrupt/timer controller. Where goes/is connected pin 31 IN1 (Sometimes called IRQ1)

For Compass II 1139 this can be pins for 8259 PIC controller, pin 19, but I am not shure.
The idea is to find out where is connected bubble memory controller's DMA request, DMA acknowledge and Interrupt request (IRQ) pins and where are connected IRQ pins on interrupt controller.
I can't do it because I don't own Compass and motherboard pictures on internet don't have good view angle and resolution to research Compass virtually via Internet.

Than you for your valuable work and information in advance.
If I had a Compass, I would be all over this.
-Thom
 

Conventional Memories

Experienced Member
Joined
Sep 26, 2020
Messages
92
Location
Belgium
Can anybody help with small reverse engineering on Compass/Compass II main board? Can you beep connections on main board from following ICs?
For Compass 1101:
1) U25 Intel 7220 bubble memory controller. Where goes/is connected pin 7 !DACK
2) U25 Intel 7220 bubble memory controller. Where goes/is connected pin 8 DRQ
3) U25 Intel 7220 bubble memory controller. Where goes/is connected pin 9 INT
4) U42 Intel 80130 Interrupt/timer controller. Where goes/is connected pin 31 IN1 (Sometimes called IRQ1)

Hi, how's the emulator coming along?
Are you still looking for someone to check on a 1101 motherboard? I'll be working on my 1101 somewhere in the coming weeks. Also what motherboard revision are those based on? The 1101 had several with different layouts and chip designations AFAIK.
 

JDat

Member
Joined
Jul 26, 2022
Messages
16
Hi, how's the emulator coming along?
Are you still looking for someone to check on a 1101 motherboard? I'll be working on my 1101 somewhere in the coming weeks. Also what motherboard revision are those based on? The 1101 had several with different layouts and chip designations AFAIK.

Hello! Thanks for interest!
Emulator. So far It somehow boots from bubble memory, but with visual artifacts. Probably because I have wrong CCOS version for my 1101 emulator. Fixed some bugs related to RTC and timing emulations, But... I stalled emulator development. Need to finish GPiB controller and GPiB FDD/HDD emulation.

Regarding pinouts and connections. I already figure out enough info from CCPROM to emulate Bubble memory and GPiB, so real need for motherboard beeping with multimeter for emulator. BUT...! I really want to draw full motherboard schematic, so need much more beeping and access to physical motherboard. Theoretically it is possible to do it remotely via video call (no nudes, please!) with somebody, who have motherboard, patience and interest in reverse engineering. With schematics it looks possible to reverse PAL contents. One PAL IC is located near RTC TMS9914A and UART. It usually get damage from leaked battery. I thing I can figure out contents of PAL if I know all PAL's connections on motherboard.

Regarding revisions of 1101, I don't have much information how many revisions are on wild. I only saw two motherboards: one from 1100 and one from 1101. My research is based on 1101 board. Link to my motherboard with IC identification. And copy of my personal GRiD Compass folder online.

Other news: We are small international team on Telegram with one Ukrainian (Author of Compass for MAME), one Kazakhstanian (Author of GUI app for GRiD Disk editor), one Latvian (me) and 2 Russians (Kirill (youtube, github) and Yuri). Mostly speaking Russian, but we can switch to English, so everyone welcome. Slowly working on Raspberry Pi based GPiB FDD (and later HDD) emulator. Have some progress and have some fails, but looks like it is doable with some patience and time.
 
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Conventional Memories

Experienced Member
Joined
Sep 26, 2020
Messages
92
Location
Belgium
Regarding pinouts and connections. I already figure out enough info from CCPROM to emulate Bubble memory and GPiB, so real need for motherboard beeping with multimeter for emulator. BUT...! I really want to draw full motherboard schematic, so need much more beeping and access to physical motherboard. Theoretically it is possible to do it remotely via video call (no nudes, please!) with somebody, who have motherboard, patience and interest in reverse engineering. With schematics it looks possible to reverse PAL contents. One PAL IC is located near RTC TMS9914A and UART. It usually get damage from leaked battery. I thing I can figure out contents of PAL if I know all PAL's connections on motherboard.

Regarding revisions of 1101, I don't have much information how many revisions are on wild. I only saw two motherboards: one from 1100 and one from 1101. My research is based on 1101 board. Link to my motherboard with IC identification. And copy of my personal GRiD Compass folder online.

Other news: We are small international team on Telegram with one Ukrainian (Author of Compass for MAME), one Kazakhstanian (Author of GUI app for GRiD Disk editor), one Latvian (me) and 2 Russians (Kirill (youtube, github) and Yuri). Mostly speaking Russian, but we can switch to English, so everyone welcome. Slowly working on Raspberry Pi based GPiB FDD (and later HDD) emulator. Have some progress and have some fails, but looks like it is doable with some patience and time.

Wow that's very cool, Awesome to see so much development going into the Grid compass.
I'll attach 2 pictures of Compass 1101 motherboards. the first one is mine and looks to be the same as the picture you have. The second one is one I've worked on for a friend and looks a bit more integrated. It seems to have an unpopulated expansion header connected to the RAM, so maybe this motherboard was also used on 1109 allowing for a RAM expansion? I also have access to this 1101 if it would prove useful. Would love to try and make a RAM expansion one day.

20230822_123416.jpg 20221229_014441~2.jpg

I'd love to contribute to the emulator or GPIB emulation but I'm afraid that I wouldn't be able to contribute much. I'm no good at coding at all so..
I would however be happy to help you out with some tracing with a multimeter, But a full motherboard like this would take weeks wouldn't it?
I haven't done much with PAL's before but would reverse engineering the PAL itself not be possible? With something like this: https://github.com/DuPAL-PAL-DUmper/DuPAL_Board

Feel free to DM me or hit me up at conventionalmemories@gmail.com if I can help in any way.

Something like a raspberry pi based drive emulator is exactly what I've been hoping someone with more skills than me would be working on.
 
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