GE Soft Eagle resurrection attempt

[Administrator]

Over the last two years I collected some parts of the ghostly GE Soft Eagle TT clone computer.
Unfortunately there is not much known about the system at all.
The concept was to design a computer that mimics most TT features, is mostly software compatible to the TT. It was planned to develop add-on cards like a i80x86 PC or PPC. But honestly: if you look at the expansion slot's signals you will recognise that these are just 68030 signals. So even a 68040 with its totally different busses would be an engineering effort. The mainboard was layout to fit in an AT style PC housing with AT style PSU power connectors of the time. Good decision I think. The Eagle features eight so called EagleChannel slots. These are proprietary interfaces and are more similar to VL-BUS than PCI i.e. more taylored towards a CPU (68030 in this case) than a generic bus (like PCI).
In two points the layout differs from PC mainboard layout. You will neither find a CPU or FPU socket nor DRAM sockets/SIMM slots on it.
These are located on two add-on cards. One card holds the CPU (PGA socket) and the socketed FPU. The CPU/FPU card layout allows to either populate a PGA socket for the FPU or the PLCC version. Nice.
DRAM memory is located on a separate add-on card: five (!) banks with four 30pin SIMM slots each. A lot of capacity on the address and /RAS, /CAS lines to drive!
According to the interviews with GE Soft main developer Gero Anschütz published in the German ST Computer magazine they planned to put the memory on the mainboard with up to 16MB ST-RAM and up to 256MB TT-RAM. Probably only 10MB ST-RAM would be usable like in the TT due to the memory space occupied by the VME slot starting at $FE000000. So it it not known if the memory add-on card can make use of 16MB SIMMs. As these are rare items - probably more rare then hens teeth - I would be happy to just use 4MB SIMMs.
This brings us to the last add-on card available: the EagleChannel-to-VME interface card. This probably will interface the system to existing VME cards - mostly graphic cards. But the VME interface card uses a backplane to triple the amount of available VME slots to be populated. Side note: most cards and their software drivers will assume that they are the only VME card and will probably assume they all start at $FE000000. Well, who wants to throw the first stone at the developers for that?
As the GAL sources and driver sources for the Nova graphic cards are still maintained by atari-forum.com user Idek Tramielski I do have some hope to move the Nova's address space away from $A00000.
So folks, that's it for the moment. I will post more information and pictures at some point later.

[Administrator]

I was in the mood of taking some snapshots of my Eagle inventory today:

These are two CPU/FPU cards. One with PLCC 68882 and the other with the PGA version


The mainboard which contains much of the I/O subsystems:

1. AT style power connector
2. 80C31 (compatible) microcontroller with EPROM for the firmware for connecting an AT style keyboard
3. MIDI interface
4. two 6850 ACIAs
5. Yamaha/GI PSG
6. DS12887 RTC like in the Falcon030
7. Parallel port
8. MFP 1
9. MFP 2
10. Serial 1
11. Modem 1
12. LAN (driven by SCC)
13. Shugart Bus (FDD)
14. SCSI 50pin
15. SCSI 25pin
16. Modem 2
17. Serial 2
18. FDC
19. ACSI
20. TOS ROM sockets
21. Cartridge Port

The RAM (ST-RAM and TT-RAM) was located on an extra board capable of taking 20 30pin SIMMs. Surely 1MB and 4MB maybe even 16MB SIMMs.


Finally the VME interface card. If and how the available 16MB address space is divided into segments for each of the three VME slots is still a mystery to me.

As you probably have noticed there is no onboard (i.e. on the mainboard) display connector for VGA/ECL. GE-Soft omitted the TT's graphics capabilities in favor of using a VME graphics card for screen output.
As you can see on the mainboard picture there are four 28pin sockets beneath the 32pin sockets for TOS. My guess is that GE-Soft hoped for acquiring a source code license to adapt TOS 3.0x to the Eagle and removing all screen related stuff in TOS including the VDI. With some reduction in code size their Eagle TOS might have fitted into four 27C512 EPROMs - reducing cost in 1994 to some degree.

So right now I have done a layout in Eagle (by CADSoft) to attach the diagnostic software ROMs to the Eagle's 40pin cartridge port connector. Hopefully it will be able to output some diagnostic messages to Modem 1. We'll see...