Do I need an adapter for TMS2564?

[eKretz2358]

Hi all, I just ordered an S40 Pro and need to program some TI TMS2564 EPROMs. The programmer is still in the mail. Can I do this directly in the programmer or do I need any sort of adapter? I am still new to this. Thanks for any advice.

[Dataman (Neil Parker)]

Hello,

The TI TMS2564 device in DIP28 package is supported on the Dataman-40Pro without the need for any package adaptors.

The 40-way ZIF socket on the programmer will accept any device in DIP/DIL package with 300mil to 600mil body width.

If you have any more questions, just let me know.

[eKretz2358]

I got into the demo mode on the software and figured that out yesterday. Thank you for the reply anyway. I will be trying my first few EPROMs sometime this week, hopefully it will be smooth sailing. If not, I may have a few additional questions, thanks.

[eKretz2358]

New question, but related. I've just discovered that some of the EPROMs are TMS27128JL-25 instead of TMS2564. The programmer database does not seem to have an entry for these that is an exact match. Are they compatible with the 40Pro? I believe they were programmed in a fashion to replace the original TMS2564s. The 40Pro does seem to read them if I tell it that it's reading a TMS2564, just not sure if that would also work to program them?

[eKretz2358]

Upon a little further reading, I've found that there is a plain "TI 27128" in the device selection menu and am assuming that it's what I needed to be looking for. With this selected in the menu, I am reading the EPROM and showing addresses programmed only from 2000 and up, but it's only using 16kb of the memory, so that's probably ok. Also discovered some "ST M27512FI" EPROMs on the boards - should these be good to go with the straight "ST 27512" setting in the device selection menu?

Edit: Hmm. I get a Read Error when I try to read one of the 27512 EPROMs with the "ST 27512" setting. If I instead use the "Generic EPROM 27512 (21V/6V/Intel)" setting then the read completes without error. Does that mean it's what I should be using then?

Secondary Edit: After seeing the 27128 note about not trying to identify those due to their not carrying identifying information, I started wondering if that might be what could possibly be causing the read error failure with the "ST 27512" setting since I'm pretty sure these are replacements programmed such that they are mimicking a 27128. I disabled the "fail on improper identification" device setting or whatever the specific wording was, and was able to get a successful read at that point. Still not really sure whether I am on the right track with that device selection or if I should use the other? Any advice to that effect would be appreciated. Thanks!

[Dataman (Neil Parker)]

Hello,

Sorry, I didn’t quite understand your point. I also see the TMS27128 in the software for the D40Pro.

The idea of replacing the 27C64 with the 27C128 is simply to double the content (i.e., storing two sets of 64 in the 128). In other words, the upper half of the memory would be identical to the lower half, so the upper address bit becomes irrelevant.

EPROMs have an internal ID, so it's expected that the software will report an ID check error. However, a 'Generic EPROM' implementation logically wouldn’t include an ID check.

[eKretz2358]

I did discover that about the doubling and even quadrupling (512s) during some marathon googling this weekend, thanks. So I guess my number one question currently is whether I should use the device selection for the ST device that it has written on top of it and disable the ID, or if I should use the generic 27128 device selection. After that another question: can I use a 27C128 interchangeably with a 27128? Some posts I read seemed to suggest that this would be just fine due to the decreased power consumption, but going the other direction would not be recommended. The EPROMs I am looking to program are for a software update on a 1980's CNC milling machine, so I'll be needing to program all new devices - would rather keep the old ones intact just in case.

I also saw mention of the ability to use some EEPROMs as replacements with doubling, one poster mentioned the AT29256 as useable. I'm not sure if that would be of much benefit though, as all of these seem to be mostly obsolete devices at this point though anyway. I did manage to source some supposedly OEM TMS2564s at a reasonable price, so I grabbed those.

[Dataman (Neil Parker)]

We only support the ST device as ST27128A, which is a different device the non-A version. Therefore, the only option is to use the generic 27128 device selection.

Regarding the possibility of using other EEPROM device in place of EPROM devices, this is a non-trivial question to answer and requires a deep analysis of the respective devices datasheets.

[eKretz2358]

I understand now. So I just read a TMS27128, and viewing the buffer, it is greyed out after address 03FF0, but there is still data written in the greyed out area.It is a duplicate copy of that written in the first half. The highlight legend shows other colors, but not grey. What does this signify? The end of the available memory space, I should think? How is there data written past what should be the end address? Also, isn't that last address supposed to be 03FFF? Why is it 03FF0 instead?

[Dataman (Neil Parker)]

The TMS27128 has a memory area from 0h - 3FFFh. When selected in the software, the buffer will be greyed out at any address beyond this as it is not usable. Data can be present in the buffer after this address but it cannot be programmed into the TMS27128.

The reason you see data in the buffer beyond the memory address rnage of the currently selected device is probably because you selcted a larger device previously and read or loaded data in the the larger buffer area. The buffer remains overall at the largest device size that was selected recently, but only the memory area of the currently selected device , shown in white is relevant.

The colours used in the buffer are described in the legend at the bottom of the View/Edit window: