GSETUP regarding expanded memory for IBM 5170

[alejack12001]

My opinion:

There is no single factory setting. If there was, why bother putting in jumpers to select various taps on the delay line. Periodically, Cheetah may have constructed these boards using delay lines of different delay times, and Cheetah adjusted the J2 and J3 settings according to which delay line was fitted. Other related circuitry on the card comes into consideration as well. That would explain the 'do not touch'. Just my opinion.

So maybe the "new settings wee etched into page 6-3 (i.e., see pen marks for J2 East and J3 West)" was simply the owner recording the settings as found.


Error '180002 010 202'.
A 202 error (not the usual 201), pointing to bit 4 at address 180002 (1.5 MB). Error 202 is an addressing problem concerning address bits 0 to 15.

This isn't necessarily caused by any "settings". For example, addressing problems are sometimes caused by a RAM chip that has failed in an 'addressing' way. And because it is an addressing problem, the pointed-to RAM chip (if a RAM chip) may not be the one that failed.


Post #114 configuration is:

1. AST SixPacknot fitted.
2. {IBM 512KB Memory Expansion Option} not fitted.
3. Cheetah Combo configured to provide 128 KB of conventional/base memory (starting at address 512 KB), plus 1408 KB of extended (starting at address 1 MB)

CMOS SETUP: conventional/base memory = 640 KB, extended memory = 1408 KB


You must have included IMG_5557.jpeg for me to verify the switch settings. Unfortunately, the resolution is not good enough for me to make out the settings.


For the post #114 configuration, that figure should be 1408 KB.

Going forward:
1. Provide a better photo of the switches.
2. In CMOS SETUP, change the extended figure to 1408 KB.

Re point 2 above. It doesn't make sense to me that the existing 2048 setting would cause a 202 error, but sometimes, I get surprised.

Agreed, there isn't a reference to an actual factory setting. So, my interpretation of the manual with the marks must be as you pointed out the optimum setting for the two jumpers that worked for the original owner of the board. Maybe his machine was the same or a clone, it is hard to say.

Well, I don't know how to fix an addressing error. If the error was a physical component then that can be fixed, however, addressing errors are beyond my capabilities.

If a RAM chip has failed, pin pointing it's location is a shot in the dark. In addition, testing a failed RAM chip is another avenue that I need to explore since I've had many with this board.

Per your request:

1. I have inserted two pictures with the first being IMG_5558.jpeg showing the switch settings and the second IMG_5559.jpeg being th mux J3 set as west and the cas J2 set as east.

2. I'll have to test this new setting of 1408 for the extended later and pass on the results though I would expect a 201 error. Reason is that is what I have received before.

 

[modem7]

Well, I don't know how to fix an addressing error. If the error was a physical component then that can be fixed, however, addressing errors are beyond my capabilities.

Yes, the causes are varied, and sometimes can be a 'right pain' to fix.
But at this time, it would be good to verify that the Combo's switch settings are set properly, because an addressing error may result from banks accidentally set to partially 'overlap' each other.

1. I have inserted two pictures with the first being IMG_5558.jpeg showing the switch settings ...

That photo isn't showing.

 

[alejack12001]

Yes, the causes are varied, and sometimes can be a 'right pain' to fix.
But at this time, it would be good to verify that the Combo's switch settings are set properly, because an addressing error may result from banks accidentally set to partially 'overlap' each other.


That photo isn't showing.

Well I can't explain why the pictures got caught up in the previous reply. However, I have reintroduced them again.

 

[modem7]

Well I can't explain why the pictures got caught up in the previous reply. However, I have reintroduced them again.

From post #119 onwards, the target RAM configuration has been the one described in post #114.
The Cheetah Combo switch settings you picture are for the configuration described in post #113.

 

[alejack12001]

You have devoted a great deal of your time in assisting me with implementing this Cheetah card as well as learning the correct language of the memories associated with these early machines.

I realize you thought I was directing my efforts towards the application of the 128-KB of RAM to add to the conventional or base memory when in fact I have abandoned this effort because of numerous errors encountered with the addresses of 80000+ and indicated chips from post 43 forward. I would correct one chip and find another, another, another, and etc. In fact, it looked like all the chips were defective. I am sorry if the posts from 114 and beyond were misleading since I failed to indicate my direction to setup the machine for extended memory only.

I hopped on to post 113 to extend the memory setting from the current 1-MB to 2-MB based on the added 1.5-MB card and following those settings of post 113. This result was an address error as well as continued parity check error 2.

Maybe this reply will read a measure of frustration, however, I feel that this board is defective. It’s like that box of chocolates in that “Forest Gump’ movie, “you don’t know what you age going to get when you buy from eBay.” The defect is either the RAM or the interface chips opposite the RAM banks. While the user manual and included software is extensive in its setup of RAM and I/O ports the troubleshooting is really poor. Obviously, there isn’t a schematic diagram to troubleshoot the board to determine the defect and correct it. The IBM card is still in the 5170 and providing the added 512-KB or RAM. As I mentioned in one of my earlier posts maybe 1-MB I all I can get with this machine.

 

[modem7]

Maybe this reply will read a measure of frustration, however, I feel that this board is defective.

I am lucky in that I have other suitable motherboards that I could use to determine whether or not the board is faulty.
In the back of my mind is that your motherboard might possibly have some kind of problem.

The IBM card is still in the 5170 and providing the added 512-KB or RAM.

The 512 KB of extended memory.

As I mentioned in one of my earlier posts maybe 1-MB I all I can get with this machine.

Of course, if you use no software that requires extended memory, then increasing extended memory beyond 512 KB is of no benefit.
But yes, increasing conventional memory from 512 KB to 640 KB has benefit.

Maybe get the AST SixPakPlus going (even though not a 'proper' solution for the IBM 5170). My recollection of the last status of that card is that it was giving you a 201 error that pointed to a single bit. If it was my card, I would be getting it going in a PC-class or XT-class computer.

Maybe get another 16-bit card that has the ability to fill the 512-640KB address space. And that could be a card dedicated to that particular task.

 

[alejack12001]

Some history on the 5170. I bought the machine from a seller on eBay in January this year. The 5170 came, damaged from fall either by the seller or the shipper. I got the seller to refund me for a replacement AT power supply that was a result of the damage to the machine. Inside of the 5170 was a 1.2 MB floppy drive, DTK 386DX motherboard, IDE controller, MDA video card and case. The 386 motherboard will have to be tested once I remove the Dallas RT clock and replace it with the RT kit that is available. The Dallas is quite dead. At first, I wanted the 5170 to be as authentic as possible. I replaced the 386 motherboard with the acquired IBM type 3 motherboard. However, my use of the GoTek and XT-CF cards did modernize the machine.

The IBM Type 3 motherboard was acquired from eBay in April. The seller still has the sister of the board still on the eBay website. The seller gave a 90 day warranty with the purchase of the motherboard that it was operational and from a working system. I have been contemplating on getting the sister motherboard as backup.

The Cheetah was purchased also from e-Bay about two years ago. At that time, I was working on a IBM PC-XT/286 clone. IBM Motherboard for that machine is very hard to get and expensive. I didn’t notice its physical size of the memory card until I installed the Cheetah that was too tall for my XT case. I held on to it until I started working with the 5170.

Right now my plan for the 5170 is to use the IBM 512 Extended memory card for added 512 memory. Then search for either another 512-kb IBM board or the 2-MB card so listed on minuszerdegee website.

It’s clearly evident that the Cheetah and AST cards are not compatible with this type 3 motherboard. I don’t have a history for the type 3. What I mean by that is the motherboard could have been used in a platform for industry or college or business or government facility that didn’t require the 640-kb of RAM and it may have gotten burned into a state that rejects added memory cards other than it’s own brand. I ran into something similar to this in a IBM laptop that I repaired for a fellow. The laptop rejected Toshiba hard drive until I got an IBM hard drive for the laptop then it responded correctly.

Thank you for all your help through out this project. I just may have to fins another path to follow.