Unknown XT class SBC CPC-010 ROM dump and explanation

[P-man]

I found this ISA card recently and thought it was an EGA video card because of the DE-9...

Etched with : 61-020066-00 and screned with NT2V0 DC 9046 #515001-01

Turns out it is a single-board computer. I went to the local junk shop and got myself an ISA backplane and once I plugged in a Hurcules card i got some life out of it!

Then i had to figure out where the keyboard went in, and speaker output.. then i could actually use it!

The rom is marked CPC-010 and it has an NEC 10mhz V20 cpu with 256k ram. I can't get it to go into full speed mode, its running at 4.77mhz currently. I was suspecting ti might have a keyboard shortcut for speed changing but ctrl/alt +/- don't yield any increase.

There's a couple more jumpers on the pcb but what looks like a good candidate for turbo doesn't seem to do anything.

Anyhow, here is the rom, photos and a brief rundown:

J3 (keyboard):
1 - CLK
2 - Data
3 - unusued?
4 - GND
5 - N/C
6 - +5v

J4 (Speaker)
1 - Audio
2 - N/C
3 - N/C
4 - GND

J5 - RESET

J6 = can have jumper installed or not, doesn't affect speed - not sure what it does.

If anyone has any insight on the BIOS (27C256 mask rom) it'd be nice if there's something buried in the code there that would indicate its 'turbo' function from a keypress which i'm sure it must have.

thanks!

 

[SuperSVGA]

Looks like the Faraday Micro PC.

You have the right clock crystal for the FE2010A to run at 9.54MHz, but to get that speed a configuration register has to be set. It probably needs a utility or something to set it, not sure if that BIOS has anything built in. Or you could probably use DEBUG.EXE to write directly to the register if you had to.

 

[ross.dykes]

Sergey Kiselev has a write-up on the FE2010A XT chipset in github: https://github.com/skiselev/micro_8088/blob/master/Documentation/Faraday-XT_Controller-FE2010A.md.

If you poke through the source for his 8088 bios, it seems that port 63h is the chipset configuration register that controls clock speed:

Data Bit	Function
0	Disable Parity Checker
1	Enable 8087 NMI
2	On Board RAM size (bit 0)
3	lock register (bits 0-4)
4	On Board RAM size (bit 1)
5	Fast Mode (0 RAM wait states)
6	7.15 MHz CPU clock
7	9.54 MHz CPU clock

The exact value to write to the register would depend on system configuration, but setting bits 7 and 6 high and bit 5 low will give you a 9.54MHz system clock and only 2 memory wait states. Setting bit 5 high sets the memory wait states to 0 which might work but I found that the video card in my system (NuXT) can't handle that.

You could use debug in DOS to write to the port, if you're just using what is on that board then the value is likely to be c4h (11000100) (256k RAM w/parity, don't lock the config register, 2 memory wait states and 9.54MHz clock). 84h (10000100) would give you the same thing but with 4 wait states.

 

[P-man]

Well, some good progress here - I found some posts on Vogons about the NuXT which uses the same Faraday 2010A, and that someone had written a SETSPEED utility.. it works great on this Micro PC!

Now to work out increasing the ram size...

 

[Plasma]

Should be easy to increase the RAM with a card like this. Most clone BIOSes will autodetect the RAM installed, at least up to 640K.

 

[P-man]

Should be easy to increase the RAM with a card like this. Most clone BIOSes will autodetect the RAM installed, at least up to 640K.

Thanks yeh I'm aware of this option, but i would like to keep on original hardware as thats cheaper - and what I have to hand

Right now i've been trying a Seattle Computer Products SCP 134C (RAM +3) ISA multi-I/O board but its very old and decrepit. That has another 256k onboard it, and dips are set to have it appear at the 256k mark from what i see, but the MicroPC bios or DOS does not see it.

I migh try throwing a GLaBIOS in there to see if it handles that better, also the author tells me i can probably do the speed change from a hotkey press instead of running the utility... I'll report back on that.

 

[P-man]

Also, I found J6 is for external NMI, and will be checking out a modified BIOS later.

https://github.com/640-KB/GLaBIOS/releases/download/v0.2.5/GLABIOS_0.2.5_VF.ROM