HCR Micron Plus EPROM Programmer

[Super_7b]

Hi Dave,

At long last I managed to get the Programmer completed. Essentially, it should have worked first time, but a faulty 34 way IDC socket (pin 34 was slightly sprained and didn't make contact) caused "Programmer not connected" errors. A few minutes with a continuity tester located the fault and after crimping on a new socket, all was well.

I decided to go for a case and found this at Rapid Electronics:-

Hammond 1456FG4WHBU Sloped Enclosure 189x165x107mm Aluminium Blue/Beige

It is the perfect size other than being a little taller than the original looks to be, due to the steeper front slope, but the PCB fits the main panel perfectly with a few millimetres to spare on the width.

I didnt want to mount the ZIF directly to the board and couldn't install it in a socket, so I designed a standoff using 2.54mm Turned Pin Single In Line SIL Headers, 2.54mm Male Pin Header Single Row PCB Connectors and two adapter PCBs I created in Kicad and had JLCPCB make. I had the minmum order thing, so I got 5 panels with 10 PCBs on each, so I have many spares . This adapter allowed me to connect the ZIF and standoff to a turned pin socket on the main board.

Not wanting trailing fixed leads, I fitted a panel mounting IDC Cable socket on the back of the case, along with a panel mounting TruConnect 2.1mm Single Hole Chassis Socket. These feed the main board via short internal cables. The connection to the BBC is via a 34 way IDC ribbon and the power supply you recommend plugs to the 2.1mm socket. The only compromise was that the panel mounted IDC socket is 40-way as I was unable to locate a 34-way version. Sadly, after completing the long oblong cutout for this, I found RS Components do have a 34-way version .

None of my EPROMs are blank, sadly, so it looks like I need to invest in an eraser.

In the interim, I will see if I can locate a couple of 2764's and 27128's on ebay. I think I saw an old post from 1024MAK which said 200ns access time or better should work.

When I run the software, if I tell it I have a 2764, I can do Copy, Blank Check, Program (Green light comes on) and Verify. All are successful and List Buffer shows all FF's, so it should work fine with a real EPROM.

I attach a few photos showing the external and internal views and a closeup of the ZIF and standoff.

I'm not sure why they are rotated from my camera view, but I seem to recall others have had this issue. Can they be corrected?

Thanks for the great product and the support along the way.

BR

Mick

[hoglet]

Very nice indeed!

Mine's still just a bare board

[atsampson]

I've built mine today, with a mix of old and new parts:

No problems putting the board together or calibrating the programming voltages. The only minor suggestion I'd make is to increase the size of the holes for the larger resistors as you've done with the 1N5819 - I used some "period" 3k3 resistors with thicker legs that only just fitted. The ZIF socket is sitting in a turned-pin socket on the top side.

I built the software and loaded it into sideways RAM, which worked fine. Detecting the board failed initially, but poking around with a logic probe revealed that one of the data lines was missing, and cleaning the 1MHz Bus socket fixed it. Burning the software into an EPROM then worked; I've since tried it with various different kinds of EPROMs and everything seems to be working nicely - thanks very much, hoglet!

Disk I/O in the software seems to be a bit slow (while reading, programming and verifying are all pretty snappy) - I wonder if it'd be worth making it use OSGBPB?

[hoglet]

The ZIF socket is sitting in a turned-pin socket on the top side.

Nice that you found one that can be socketted.

Do you happen to know the Harwin part number?

I've since tried it with various different kinds of EPROMs and everything seems to be working nicely - thanks very much, hoglet!

What Eprom types have you managed to test?

Disk I/O in the software seems to be a bit slow (while reading, programming and verifying are all pretty snappy) - I wonder if it'd be worth making it use OSGBPB?

In my experience, OSGBPB is much slower than OSFILE on older DFS-like file systems, because it just uses OSBYTE one byte at a time. It's better in ADFS and NFS and later DFS, but I can't imagine it would ever be faster than OSFILE.

What filesystem are you using?

Dave

[atsampson]

Do you happen to know the Harwin part number?

Nope, sorry - it's one I've had sitting around for a while. It's probably 1990s at the newest; I can't see anything like it in Harwin's current catalogue.

What Eprom types have you managed to test?

I've written Mitsubishi M5L27512K and ST M27128A, both 12.5V. I've read RS 2764, Fairchild MBM2764, MBM27C64, MBM27C256A, TI 27C64, AMD AM2764, Mitsubishi M5L27128K, Toshiba TMM27128D, TMM2764AD, and NS NM27C128Q.

What filesystem are you using?

It was DFS 0.9 - I've replaced it with JGH's DNFS 3.02 ROM now which seems a bit quicker (although I've not measured anything).

[atsampson]

Just written a Fairchild MBM2764 successfully as well - that's a 21V part.

[hoglet]

It was DFS 0.9 - I've replaced it with JGH's DNFS 3.02 ROM now which seems a bit quicker (although I've not measured anything).

I don't think any of the 8271 DFSs buffer OSGBPB calls, so they would be significantly slower than OSFILE.

Just written a Fairchild MBM2764 successfully as well - that's a 21V part.

Nice, thanks for the update on successfully tried parts.

Dave

[Super_7b]

Hi All,

I have successfully used the EPROM Programmer on a variety of chips (2716,2764,27128) with no trouble. However, I have some fast access chips (WS57C43C 55ns access time) which are "Pin Compatible with 4K x 8 Bipolar PROMs" that I cannot program.

They check as blank but after programming, they fail the validation and subsequently show as still blank.

From the data sheet (attached) they require "VCC = 6.25 V ± 0.25 V, VPP = 12.75 ± 0.25 V" and "tPW Program Pulse Width 100 to 200 μs" to program them. I wonder if the 2732 settings (having manually selected the 12.5V programming voltage) are just not right. I also include the data sheet for the NMOS 2732 for comparison.

I am no expert at the fine details of the specifications, so can anyone help here?

BR

Mick

[hoglet]

From the data sheet (attached) they require "VCC = 6.25 V ± 0.25 V, VPP = 12.75 ± 0.25 V" and "tPW Program Pulse Width 100 to 200 μs" to program them. I wonder if the 2732 settings (having manually selected the 12.5V programming voltage) are just not right. I also include the data sheet for the NMOS 2732 for comparison.

I am no expert at the fine details of the specifications, so can anyone help here?

Just looking at the HCR software disassembly, the 2532/2564/2716/2732 parts (all 24 pin devices) share common programming code which uses a single 50ms pulse. That's much longer than allowed by the WS57C43C and may well cause damage. So I don't think it will be possible to program these with the original HCR software.

Dave

[Super_7b]

Just looking at the HCR software disassembly, the 2532/2564/2716/2732 parts (all 24 pin devices) share common programming code which uses a single 50ms pulse. That's much longer than allowed by the WS57C43C and may well cause damage. So I don't think it will be possible to program these with the original HCR software.

Dave

Thanks for the response Dave.

Doh!

Mick

[Halifask]

I've ben looking for a programmer on eBay and Marketplace but they are few and far between and usually don't have the software.

Just came across this topic and I'm wondering if I should build one, do you still have PCBs for it?

Arthur

[hoglet]

Just came across this topic and I'm wondering if I should build one, do you still have PCBs for it?

I have one PCB left (for £15 inc UK postage).

PM me if you are interested.

It's not a cheap project to build though....

Dave

[Halifask]

When you say "not cheap" at a guess (won't hold you to it) how much?

Arthur

[hoglet]

When you say "not cheap" at a guess (won't hold you to it) how much?

I would guess £70(ish), but that will depend on whether you have to buy absolutely everything.

DAVE

[Halifask]

That's not too bad bearing in mind folks are asking for £50+ for one with no software that may or may not work.

Could be a good learning project.

I'll take the PCB and I have the BOM so I can look into getting the rest of the materials.

When it comes to it I may need a bit of guidance on the software as I've not done that before but I'll sort the hardware first.

Could you let me have the details for payment please.

Arthur

[hoglet]

Could you let me have the details for payment please.

PM sent...

[Super_7b]

From the data sheet (attached) they require "VCC = 6.25 V ± 0.25 V, VPP = 12.75 ± 0.25 V" and "tPW Program Pulse Width 100 to 200 μs" to program them. I wonder if the 2732 settings (having manually selected the 12.5V programming voltage) are just not right. I also include the data sheet for the NMOS 2732 for comparison.

I am no expert at the fine details of the specifications, so can anyone help here?

Just looking at the HCR software disassembly, the 2532/2564/2716/2732 parts (all 24 pin devices) share common programming code which uses a single 50ms pulse. That's much longer than allowed by the WS57C43C and may well cause damage. So I don't think it will be possible to program these with the original HCR software.

Dave

Hi Dave,

Dave Hitchins kindly offered to program the EPROMs for me. He tells me he had no issue with them (they are currently in the post back to me) and he also checked the ones I "sacrificed" on the HCR. He tells me they also programmed fine, so it looks like I got away with it.

I understand your remarks about the pulse length. What I am not sure about (I've tried to decipher the ROM code, but it's very complex) is if these 24 pin devices get Vcc raised during programming. The 2732 data sheet says Vcc=5V, so I suspect they don't. The 27128 (for example) gets "VCC = 6V ± 0.25V; VPP = 12.5V ± 0.3V". The apparent lack of the Vcc step might be why they never got programmed. Also, Vcc and Vpp for the 27128 et. al. might be marginally low for the WS57C43C. Any thoughts?

I realise that these devices are currently out of scope on the HCR and changes to the ROM would be troublesome, but I might have a look at it sometime. The short pulse requirement may not even be possible on this hardware as well as getting the required Vcc and Vpp.

Thanks for the help.

BR

Mick

[hoglet]

I understand your remarks about the pulse length. What I am not sure about (I've tried to decipher the ROM code, but it's very complex) is if these 24 pin devices get Vcc raised during programming. The 2732 data sheet says Vcc=5V, so I suspect they don't. The 27128 (for example) gets "VCC = 6V ± 0.25V; VPP = 12.5V ± 0.3V". The apparent lack of the Vcc step might be why they never got programmed. Also, Vcc and Vpp for the 27128 et. al. might be marginally low for the WS57C43C. Any thoughts?

The HCR programmer has two programming algorithms:
- slow (one 50ms pulse)
- fast (N 1ms pulses followed by a 4N pulse).

I think VCC is only raised to 6V for the fast algorithm.

The choice of algorithm is currently fixed for a given device, and all 24-pin devices use the slow algorithm.

To be honest, the code is a bit of a mess, with lots of replication. Much more could be data driven than it currently is. Adding a new device is definitely non trivtal.

I realise that these devices are currently out of scope on the HCR and changes to the ROM would be troublesome, but I might have a look at it sometime. The short pulse requirement may not even be possible on this hardware as well as getting the required Vcc and Vpp.

Everything is done in software, so a short pulse would be possible.

Dave

[Super_7b]

Hi Dave,

Over in the thread viewtopic.php?t=29090 asking for help programming the WS57C43C, I came across a couple of anomalies in the pinout for this chip vs the conventional 2732. The real killer is that Pin 18 need to be High to get output vs Low on the 2732.

This is almost certainly why I was unable to program these chips or read them when Dave Hitchins had done that for me.

Another reason why it would be a major task to get the HCR to handle these chips....

BR

Mick

[hoglet]

Another reason why it would be a major task to get the HCR to handle these chips....

The hardware is certainly able to handle the CS2 input, as pin 18 is under complete software control. I'm less sure it can generate the right shaped programming pulse on nCS1/VPP:

What's unusual here is the requirement to pulse VPP between 5V and VPP for each byte. On all the EPROMS supported by the HCR programmer, VPP remains constant during the programming phase, and the programming pulse(s) is applied to one of the other pins using normal logic levels.

The hardware is not capable of switching VPP rapidly between 5V and VPP, because of C16 (4u7) on the LM317 adjust pin. (See page 6 of the schematic ) It takes, for example about 10ms for the VPP regulator voltage to rise from 5V to 12.5V. Given this slow rise time, it's hard to see how you would generate a 100-200us wide pulse.

Dave