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Jumping to program in TPA?

atod

Experienced Member
Joined
Oct 14, 2010
Messages
303
Location
New York, NY
Folks,

I'm in the process of bringing up CP/M on my CCS 2422 FDC / 2810 CPU combo. So far, I've hacked up my monitor to correctly receive and transmit Intel hex (to/from RAM) over serial. I'm able to load RAM with CCBIOS (for these cards) and CPM 2.2 image (BDOS + CCP). When trying to enter CP/M from warm boot vector, I get "CPM 61K" then "Drive Select Error"

My problem is my 8" disks are not formatted, so I think all the sector seek read low level ops are failing in BIOS and the Monitor. The disks need to be formatted on a per track basis. Saving myself from developing the format code, I'm trying to use one of CCS's programs that does that job. It's called CCSINIT.COM.

I then load CCSINIT.COM (as hex with correct offset) into 0x0100 (TPA). I jump to it from the Monitor however it's exiting out.

Does anyone know of tricks to get TPA to run even if CCP/BDOS initialization routines haven't completely run? Anyone with code snipits for WD 179X formatting routines?

Thanks
 
Have you set up CDISK (location 0004) correctly in your BIOS initialization? Leaving garbage in that cell will lead to grief.

There's no reason that a program can't be made to run without an initialized BIOS as long as the program makes no BDOS or BIOS calls. I strongly suspect that CCSINIT does make such calls.
 
Hi atod,

If the program calls to BDOS (or BIOS), You'll have problems (for example, writting to the screen the copyright or title).

One posibility is to do changes in CBIOS to support a ram drive and load there your format utility.

In that case, the book THE CP/M HANDBOOK by A. J. LAIRD can help you.

Good luck!
 
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