510 board build

[bxdanny]

The same code is used for the $FFxx page on both serial and video systems. It fills $D000-$D7FF with $20 in order to "clear the video screen". It even writes the "H/D/M?" prompt into RAM at $D0C6. On a serial system (identified by having $FE01=$00, the second byte of the 65A serial monitor code), each character is ALSO output to the ACIA at $FC00 by calling the routine at $FE0B. So CP/M, 65U Level III, or any other code that uses the $D000 block of RAM will always have it erased by a reset.

[Klyball]

Well that answers that question, So my problem must be some were else, I will check and see if somehow the data is getting overwritten when the processor is switched.
I had just assumed that it was , when I reset and checked the memory it was changed.
I will boot from the c3 utilities disk into 65D and write to D000 then invoke the z-80 monitor and read the memory with that.

Thanks for the insight as I was going way down the wrong path, I should have seen that right off.

[Klyball]

I finally tracked down the problem to the clock circuit, it seems the z-80 does not like to run at 1mhz which is the clock speed of the board, the schematic has a table showing the z-80 should be running at 2mhz all the time and you should be able to switch the 6502 between 1mhz and 2 MHz but its not the case.
Also the processors use the 02-vma ,vma lines for z-80 and 6800. I made the appropriate modifications to the 610 board
in the mean time I isolated the z-80 clock line and using my signal generator gave it 2mhz.

H/D/M?D
49K CP/M Rev. 2.24
for Ohio Scientific C3
Copyright (C) 1980, 81 by Lifeboat Associates

A>DIR

A: PIP COM : STAT COM : LOAD COM : DDT COM
A: XSUB COM : MEMR COM : COPY COM : OSIGEN COM
A: FORMAT COM : OSILNKS ASM : WFBIOS COM : ED COM
A: SUBMIT COM : ASM COM : DUMP COM : DUMP ASM
A>A>WFBIOS

WFBIOS for CP/M Version 2.3 Exp.
for Ohio Scientific C3.

This program writes the bootstrap loader
and disk I/O routines to track zero
of the logged-on disk drive.
(CTL-C to return to CP/M)

Do you have Fast or Slow stepping disk drives (F or S)?


A>MEMR

MEMR Memory Test - Version 1.4

BIOS located at BE00 Top of memory at BFFF
Press "SP" or "^C" to warm boot at any time
or "^X" to restart test from beginning.
Response of "CR" gives default test range
which starts above this program and ends at BIOS.

Starting address (Hex or "CR")
Starting address (Hex or "CR") 0842
Ending address (Hex or "CR") BDFF
"CR" to continue test - "SP", "^C" or "X" to stop

Non-destructive test of ALL MEMORY
Bit stuck high or low test
Adjacent bits shorted test
Checkerboard (55AAH pattern) test
Walking bit left test
Walking bit right test
Address line test
Random number test 1 2 3 4 5 6 7 8
Test series complete

A>DIR
A: FERI : BASDEMO COM : F80 COM : STAT COM
A: L80 COM : M80 COM : FORLIB REL : PI FOR
A: LPTDRV MAC : INIT MAC : LUNTB MAC : IOINIT MAC
A: LIB COM : CREF80 COM : TEST BAS : TEN MAC
A: ZBIOS ASM : OBASIC COM : RANTEST BAS : TEST
A: LOAD COM : ASM COM : DDT COM : ED COM
A: SYSGEN COM : SUBMIT COM : DUMP COM : CP/M MAN
A: DSKDRV MAC : BASDEMO BAS : MEMR COM : BASDEMO DOC
A: TEST C : TEST MAC : PRN : HEX
A: TEST PRN : TEST REL : TEST FOR : F80TEST REL
A: BENKO BAS : TESTOBJ REL : FORLIB LIB : PIP COM
A>BASDEMO
BASIC Compiler/Interpreter comparison demonstration
(C) Copyright 1979, Lifeboat Associates


There are two tests to run:
A) The first test concatenates a single character
to a string variable until it is 255 bytes long.

B) The second test does a SHELL-METZNER sort on a
numerical array of up to 1000 elements.

Which test? A or B?

How many concatenation cycles (50 will take less than a minute)? 50

CONCATENATION TEST BEGINS NOW...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41
42 43 44 45 46 47 48 49 50

TEST COMPLETED

The second disk is labeled Fortran!!

[Klyball]

Well, after finding a bad 7410 I now have the clock circuit working properly switching from 1 to 2 Mhz.
But after the fix I was back to no z-80 so I determined it was not the clock, both the 6502 and 6800 seemed to be working properly so I concentrated on the z-80 circuits. i could not find anything obvious and it seemed to start working then freeze, I hooked up my 16700 and verified at least the system was trying to start but then would lockup. after further investigation I found that the NMI,IRQ, and WAIT line were floating.
Examining the schematic I found the 3 pullup resistors were not installed one on the DD line also.
After adding the pullups its working like a champ(im surprised the 6502 and 6800 were ok in this state)

I also found Obasic for cp/m which is super cool also.

Now I need to find or write a way to make Dumps of these 8" disks to get them archived for Dave.

On to OS65U

[Klyball]

Found the terminal for my 510 build, one less piece of the puzzle.

DSC_0212a.jpg (374.23 KiB) Viewed 14797 times

[glitch]

I've got OS-65U for serial systems, but no way to image 8" disks at the moment. I keep saying it's a long-term project to write some 8" disk imaging code...