The Fluke 9100A Tester
The 9100a tester is a 1988 vintage microprocessor test device. You plug a processor-specific pod into the processor socket, and it allows you to look around inside the machine. It is not an in-circuit emulator. I don't think that it can actually run a program in the target system. But it can run scripts that allow for debugging and test of boards. My specific interest is to use it for pinball machine boards using a 6809 processor.
A few useful links:
The Tech Tools Archive where you can find lots of posts on the 9100a
The signup page for the TechTools mailing list
Link to manuals
ftp site at flippers.com lots of useful Fluke 9100 (and other) stuff
Art's 9010A pages - Art sells 9010A and pods, and has other info on these things.
Pods that I have
the machine disassembled on my office floor. It is apart because it has
- A failing Miniscribe HDD
Replacing the Floppy Drive
Here's a picture of the logic board for a TEAC FD235GH floppy disk drive. Floppy disk drives have evolved to be $10 devices that ship with a minimal configuration. Lots of pins are disconnected, and the drive is soldered for DS1 (i.e. the "second" drive in a system) to eliminate the need for twisted floppy cables in the PC.
Our job is to restructure the drive so that it lines up with a 1988 floppy configuration.
Here are the details on the 9100a floppy interface.
Unfortunately, there are two problems. Floppy disk drives have not had a /ready line for a long time. And the /CHANGE signal is the wrong sense for the 9100a, which expects the signal to be a CHANGE signal.
The solution is to hack the drive and use drive select to also fire up the motor and drive the ready line. The CHANGE line has to be connected to ground, which can cause problems. Here's what I did:
Open floppy drive
I have validated this by formatting and copying 720KB floppies. 1.44MB disks result in CRC errors - wrong bit rates.
The system now boots from the system floppies. But there's a catch. Somebody decided to implement the disk change line to help me switch floppies. So the stupid thing thinks that disk#2 is still disk #1. No idea why they would have done this. The fix was to pull the drive connector, faking a change signal.
Upgrading the EPROM
We need to do this to enable the most up-to-date SCSI driver so we can escape the death grip of a Miniscribe hard drive. Not too hard. First, you need a pair of 27C512 EPROMs. I tried to buy mine from Fry's, but my local store only had one and the next closest store was out of stock. the third store had them, but I got them home only to find that they were 27C256. I found some clean new TI parts at HSC for $2.82 each. Programmed them up and inserted them. You have to cut W2, which is the second jumper down on the left hand side of U28. It is unlabeled, so you have to look at the manual - or take my word for it.
|These are the EPROM files that I used.
|Making Floppy Disks
Everything has a story, and this is a long one. For now, just a few bits and pieces on the right that actually worked.
9100A_upgrade paper on the SCSI upgrade