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Compass II wanted (1129, 1139)

tschak909

Experienced Member
Joined
Mar 26, 2018
Messages
96
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
11
Sounds interesting. I am working on GRiD Compass emulator. We can share knowledge.
 

tschak909

Experienced Member
Joined
Mar 26, 2018
Messages
96
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
96
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
 
Last edited:

JDat

Member
Joined
Jul 26, 2022
Messages
11
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
11
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
11
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
96
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
 
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