Building the KLyball D-13

[Jeff]

So far using the KLyball 610 board with my original 600 board the memory errors are completely different than with my memory board. They are still there, but very different. What happens with the 610 board is that on every 16th run through the memory test almost every byte between 12352 and 13311 shows an error such that the value is off by exactly 16. I'll get the errors on the 16th run, the 32nd run, the 48th run, etc... Never do I get an error on any other run, or in other locations. I've replaced the memory in that 1K block and the surrounding blocks. Same thing happens. The code I'm using is below, modified to concentrate on those locations. It would be great is someone else could give it a shot and let me know what they get.

Code: Select all

10 X=0:Y=0
100 PRINT"INITIALIZE MEMORY"
110 FOR I=8192 TO 27647
120 POKE I,X 
130 NEXT I
150 PRINT"BEGIN MEMORY TEST"
180 X=X+1
190 IF X>255 THEN X=0
200 FOR I=12351 TO 13312
210 Z=PEEK(I)
220 IF Z=Y THEN GOTO 300
230 PRINT"LOC";I;Z;"S/B";Y
300 POKE  I,X 
305 NEXT I
310 Y=X
315 PRINT"*";
320 GOTO 180

I ran your code here on my SB2 and Replica 610 and all I get are 3 rows of asterisks repeating. Is that what is supposed to happen? I have all the memory populated on my 610. Let me know if there is anything else you want me to try.

SBII.jpg (72.35 KiB) Viewed 46420 times

/Jeff

[Jeff]

Here is a corrected diagram (I had 1 trace incorrect) for the Dual Sided Floppy Mod for the 505 board. I also placed all the jumpers and cuts on the component side.

Mods for Dual Sided Floppy 505 board.jpg (154.59 KiB) Viewed 46418 times

/Jeff

[BillO]

I ran your code here on my SB2 and Replica 610 and all I get are 3 rows of asterisks repeating. Is that what is supposed to happen? I have all the memory populated on my 610. Let me know if there is anything else you want me to try.

/Jeff

That's exactly what you are supposed to see if there are no errors. Thanks for doing that Jeff, it helps. I am now 98% sure that the memory problems are with my 600 board. I'll have my key switches in a day or two and will bring my replica 600D to the fray. Hopefully things will move more quickly.

[Klyball]

@Bill

your memory issues could be the problem writing to the disk do you have the same buffers chips in the 600 and 610 ie 8t28 not 8t26's

[Jeff]

Probably a stupid question but I'll ask it anyway. Can you run dual drives without each drive being dual sided?
How would you hook up a second 5-¼ inch floppy drive?

[Klyball]

The 610 and d13 with out modifications are set for dual single sided drives the side select line is connected to ds1 and disk select is ds0 so you get 2 single sided drives
after the mods you should be able to still use single sided drives because there is no side select on those drives
in theory if you added a inverter to the side select and hook it to ds2 and ds3 you could have 4 single sided drives

[BillO]

@Bill

your memory issues could be the problem writing to the disk do you have the same buffers chips in the 600 and 610 ie 8t28 not 8t26's

It is indeed the case that the memory issues are causing at least part of the problem. I can load values in to certain areas, then go back and read them and they are different.

The buffers are okay though.

[Jeff]

Can I use both the "A" and "B" connectors on the floppy cable when connecting 2 drives?

[Klyball]

As long as it does not have the twist

[Jeff]

I thought that the twist told the drive which drive it was. If no twist, then how does each drive know when to respond? Do you set the DS0/DS1 differently?