Willem PRO4 ISP? Help, can't program 2764 or 27xxx

By: asbesto - 2008-08-24 11:19:29

Hi all,

I'm new in this kind of stuff, so please be patient

I'm trying to program some old EPROM, stuff like 2764, 27128, 27256, or 27c512 ... any kind of 27XXXX, with or without "C"

I'm successful in reading them, but there's no way to write on them!

Some times I get errors, some times I write garbage, sometime it write and ... does NOTHING!

The manual with this programmer (Willem Pro4 ISP from Ebay, Tomsad) it's only a few pages, so there's no support or help.

27XXX seem to be supported.

On manual I can see that Vpp can be from 12.5 to 25V, adjustable by dip switches. Vcc from 5 to 5.5

But what about other settings?
What are tWP and tWC, and how to set them for different chips?

Also, what is the D5 switch?

I made some photos of my programmer, to be more detailed.

I'm using it under Win XP Home Edition (BLEAH! When a GNU/LINUX Software?!?), with his "USERPORT.EXE" demon running, and the latest version (0.97G) of EEPROM.EXE.

Any help is appreciated. If this is annoying, please write me on

asbesto (at) gmail (dot) com

We need this in order to restore some old Commodore PET's for our computer museum

http://museum.freaknet.org

Any help is appreciated!

Following, images of our programmer.










Hope images are not annoying.

Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: EZo - 2008-08-24 12:30:22

Your programmer should support old eproms.
Comments.
1)Use only external power for old eproms 2716...27256. Turn switch Jp10 up (external).
USB power can't handle required current and voltage drops.
Recomended to have 9-12V 500mA power supply, connector center positive.
It is better to have less stable voltage (8..9V) than high (11..15). Due to voltage drop on internal regulator 78L05 , it can temperature overloaded , Vcc and Vpp will drop.
2) Note , Jp6 and Jp7 have 4 voltage combinations : 12.5, 15, 21 and 25V. Most chips 2716 and 2732 require 25V Vpp.
2732A and 2764 require 21V, 2764A and 27256 12.5 V Vpp; usually with Vcc value 5.7...6.2v
Jp6,Jp7 settings you can find in label on programmer body bottom side.
Here can be some exceptions for particular chip, need manufacturer and full chip name to help you. Vpp voltage overload can damage eprom. Don't play with voltage set.
3) twp and twc   selected as SW default are not the best ones. Programming pulse from datasheet for 2716 and 2732 is 50ms, I prefer change 2716 default from 25ms to 10ms, 2732 default from 1.2ms to 10ms. After succesfull programming I repeat programming (overprogramming) once to be sure on reliable result. For chips 2732A, 2764 programming pulse 1.2ms is OK.
You can find my applied voltages and pulses in my test file
4) Programmer support latest SW 0.98d5, 0.98d8 (jumper your marked D5 down) , which works faster on high capacity devices and have more supported devices (most of them are PIC's). Unfortunately SW sometimes is not stable.
I prefer use SW 0.97ja , jumper D5 up.
Setup of 0.97ja automatically will load driver io.dll.
The same can do 0.97g. Here 2 another driver files dlportio required in program directory.

Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: asbesto - 2008-08-24 12:45:03

EZo wrote on 08/24/08 at 12:30:22:
1)Use only external power for old eproms 2716...27256. Turn switch Jp10 up (external).


Thank you! But:

1) I don't use USB, and

2) You say JP10 UP, but my manual says "White area indicate switch position". And for "external power" the white position for JP10 is down!

I will try your settings anyway, thank you!

Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: EZo - 2008-08-24 13:14:22

Quote:
You say JP10 UP, but my manual says "White area indicate switch position". And for "external power" the white position for JP10 is down!

Yes, you are right. Then other mentioned settings are opposite.

Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: asbesto - 2008-08-24 14:41:54

I tried this, with a 27128 eprom:

1) win xp polling on LPT device was already disabled.

2) I set up LPT port as EPP in BIOS.

3) I can read 27128 eprom.

results:

12.5 Vpp setup, 5V Vcc, the programming exit with error almost at start

15V Vpp: it reach about 15% and exit with error

21V Vpp: it goes to abour 40% and exit with error

25Vpp: It goes to 80% and exit with error.

In every case, NOTHING is written on the eprom, that is already blank!



Measuring Vpp on pin 14 and 1 on the EPROM, I notice that when the write start, Vpp goes to about 8 or 9 Volt, and suddenly drop to 6, 5, 4.5 Volt.

So, I imagine this is a problem - Vpp never reached 12.5V in any case.

p.s.

In my board, as in the upper images, I can't see any 7805!


Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: DL - 2008-08-24 15:55:16

Hi,

Measure VPP with a 50mA load.   Enter the Test H/W tab, set programmer as indicated.   You can enable/disable VPP by clicking on pin1 on the screen.   Measure VPP with a 50mA load for 12.5, 21, and 25V by inserting a resistor of the appropriate value between pins 1 and 16 of the ZIF socket.

Use 240 ohms for VPP=12.5V, 390 for 21V, and 470 for 25V.   For each combination, measure voltage with and without a load resistor.   For loaded measurements, measure right after enabling VPP and then after 2 minutes.   VPP must stay within allowed range for the second measurement.

Worst case load time is for 2716 (50mS X 2048 = 1.7 minutes).   For 2732, it should be 3.4 minutes, but the program only allows a 12mS programming pulse (1 minute).   Worst case for 27128 is over 13 minutes; timing pulse should be 1mS (M27128A) with a 3X overprogramming pulse (I don't think the program does this part).

HTH,
Dennis

Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: asbesto - 2008-08-24 16:01:57

Hi, thanks for the testing explanation, I will do as soon as possible. While waiting, I found the 7805

I measured about 18V input, and, when programming, 2.5 volt output! This is very weird, so thinking about a broken 7805 I changed it. But no way: while programming, output of 7805 drop at 2.5 - 3 volt.

I will test Vpp as you stated in a few hours

Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: EZo - 2008-08-24 16:16:50

Let check step by step.
1) Power supply alone. Measure voltage on plug. Load power supply shortly with resistor 33 Ohm (load ~300..400mA) and measure what voltage on exit.
2) Programmer , better disassembled, without eprom in socket. Keep settings as selected for 27128 , apply Vcc=5.6V, Vpp=21V. Connect power supply.
SW 0.97ja or 0.97g. Go Test H/W.
Activate 32-Vcc and measure voltages on ZIF32/32 and ZIF32/30 (ground ZIF32/pin16 , shield of USB socket, shield of paralel port connector).
Activate 1-Vpp and measure voltages on ZIF32/1 and ZIF32/pin3.
Keep activ ~1 min. Recheck voltages. Check temperature of 78L05 (next to USB connector, it has different package than 7805).
Place resistor 100 Ohm from ZIF32/32 to ground (load ~50mA). Measure voltage on ZIF32/32.
Place resistor 56 Ohm from ZIF32/32 to ground (load ~100mA). Measure voltage on ZIF32/32.
Place resistor 2.2k Ohm from ZIF32/1 to ground (load ~10mA). Measure voltage on ZIF32/1.
Place resistor 1k Ohm from ZIF32/1 to ground (load ~20mA).
Measure voltage on ZIF32/1.
Check no voltage drop within 10 sec with load.
Check temperature of 78L05.
Turn off all signals in Test H/W
3) Erase 27128 in UV light.
Place in ZIF32 socket.
Run Blank check.
Load file and run Program. What error message ?
4) Quote:
25Vpp: It goes to 80% and exit with error.

Don't play with Vpp !!!!
27128 chip with Vpp=25 can be damaged permanently now. Extra current can be taken from programmer with failed chip. Forget on success !
What chips do you have, manufacturer and full chip name ?
Come back with voltage measures and results !
---------------
DL: Quote:
Measure VPP with a 50mA load.   ...
Measure VPP with a 50mA load for 12.5, 21, and 25V by inserting a resistor of the appropriate value between pins 1 and 16 of the ZIF socket.......
Use 240 ohms for VPP=12.5V, 390 for 21V, and 470 for 25V.

We should be sure on Vpp checking with load 20mA max.
This Vpp current is max typical value from tested chips range.
Most 21/25v Vpp eproms take Vpp current 5..15mA.
If voltage converter is able keep 20mA with 21/25V, no problems to be expected with 12.7V Vpp eproms and higher Vpp currents. 12.7V Vpp can be verified with   load   50mA
Anyone Willem programmer with voltage converter based on MC34063 (even updated with improved higher current coil) can't handle 50mA at Vpp=25V !
Quote:
I measured about 18V input,

Is it your power supply voltage ?
If yes, change power supply to 9-12V !!
Programmer regulator can't handle temperature dissipation (current ~400mA, voltage drop ~12V, power ~5W ! ).
Regulator usually can't be damaged, here works internal temperature/current protection. Removing load and temperature comes back to normal, regulator is working again.
----
Regulator used in Pro4 is 78M05 (not 78L05).
78M05 can deliver 500mA with adequate heat sinking. Programmer current consumption with eproms 21/25V Vpp   is up to 400mA. High power supply input voltage (for example 18V and even 12V from recommended range), 78M05 temperature increases and regulator not effectiv more, voltage drops.
You can change regulator 78M05 with 7805 in the same package DPAK. 7805 has output current 1.0A and better thermal characteristics.





Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: DL - 2008-08-24 17:59:24

Hi EZo,
EZo wrote on 08/24/08 at 16:16:50:
We should be sure on Vpp checking with load 20mA max.
This Vpp current is max typical value from tested chips range.
Most 21/25v Vpp eproms take Vpp current 5..15mA.
If voltage converter is able keep 20mA with 21/25V, no problems to be expected with 12.7V Vpp eproms and higher Vpp currents. 12.7V Vpp can be verified with   load   50mA
This type of thinking is not logical.   I have a EE background and circuits must be designed to work for the worst case situation.   How can you tell when you have a "typical" or "worse case" device?   Designing for what you think is a "typical" case will only lead to an unreliable design.

How can you determine what is typical?   You'd need a large selection of devices from all vendors to arrive at anything that could be considered a reliable typical value.   I don't recall reading any datasheet that gave a typical (or minimum) value for Ipp.   Those values aren't meaningful when designing a programming circuit; worst case is all that matters...

To make a claim that a programmer supports NMOS EPROMs, the programmer must be able to provide Icc=100ma (the highest Icc for any device from any manufacturer) and Ipp=50mA.  Otherwise, it won't work for some devices that are within manufacturer specs.
Quote:
No one Willem programmer with voltage converter based on MC34063 (even updated with improved higher current coil) can't handle 50mA at Vpp=25V
Properly designed circuits using this device should be able to provide 1.5A reliably.   That's what the datasheet gives and I expect that value to be conservative.

Regards,
Dennis

Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: asbesto - 2008-08-24 18:18:05

Ok, now we have a nice semi-professional tunable power supply.

EZo wrote on 08/24/08 at 16:16:50:
Let check step by step.
1) Power supply alone. Measure voltage on plug.


8.40V

Quote:
Load power supply shortly with resistor 33 Ohm (load ~300..400mA) and measure what voltage on exit.


8.16V

Quote:
2) Programmer , better disassembled, without eprom in socket. Keep settings as selected for 27128 , apply Vcc=5.6V, Vpp=21V. Connect power supply.
SW 0.97ja or 0.97g. Go Test H/W.
Activate 32-Vcc and measure voltages on ZIF32/32 and ZIF32/30 (ground ZIF32/pin16 , shield of USB socket, shield of paralel port connector).


5.40V, 5.40V

Quote:
Activate 1-Vpp and measure voltages on ZIF32/1 and ZIF32/pin3.


21.0V !!!

Quote:
Keep activ ~1 min. Recheck voltages. Check temperature of 78L05 (next to USB connector, it has different package than 7805).


21.0V, 7805 quite cold
(note: now the board use a normal 7805 instead of the little one)

Quote:
Place resistor 100 Ohm from ZIF32/32 to ground (load ~50mA). Measure voltage on ZIF32/32.


5.17 using 112 ohm (56+56 )

Quote:
Place resistor 56 Ohm from ZIF32/32 to ground (load ~100mA). Measure voltage on ZIF32/32.


4.71V

Quote:
Place resistor 2.2k Ohm from ZIF32/1 to ground (load ~10mA). Measure voltage on ZIF32/1.


20.7V using a 3.3Kohm resistor

Quote:
Place resistor 1k Ohm from ZIF32/1 to ground (load ~20mA).
Measure voltage on ZIF32/1.


19.1V, resistor become quite hot (1/4W, 1 Kohm)

Quote:
Check no voltage drop within 10 sec with load.
Check temperature of 78L05.


No dropouts, 7805 quite cold.

Quote:
Turn off all signals in Test H/W
3) Erase 27128 in UV light.
Place in ZIF32 socket.
Run Blank check.
Load file and run Program. What error message ?


Blank check ok! lolading a file with something inside, programming...

Error at 0x000043 Chip = 0xFF buffer = 0x42


Quote:
4) Quote:
25Vpp: It goes to 80% and exit with error.

Don't play with Vpp !!!!
27128 chip with Vpp=25 can be damaged permanently now. Extra current can be taken from programmer with failed chip. Forget on success !


NOW I know.

Quote:
What chips do you have, manufacturer and full chip name ?


Well, a lot of 27512,256,128, mostly from Intel.
Some names are:

D27128A
D27256-2
M27128AF1
D27512
AM27C020
D27512-2
D27256-2

...and, really, a lot of other EPROMS

Quote:
Come back with voltage measures and results !


Done! Many thank you. Hope we will solve this - we have an exibition in a few days and want to restore some Commodore PET

Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: EZo - 2008-08-24 18:46:27

Quote:
Well, a lot of 27512,256,128, mostly from Intel.
Some names are:

D27128A
D27256-2
M27128AF1
D27512
AM27C020
D27512-2
D27256-2

Note all mentioned chips require 12.7V Vpp and 5.7..6.2V Vcc
Only 27128 works with 21V Vpp.
Try restore your Commodore with compatible eprom M27128A. It has less currents and maybe programmer is able handle it without mods.
Quote:
5.17 using 112 ohm (56+56 ).... 4.71V

Vcc drops significant !! It can cause a failure. I will check used transistors in programmer and will be back.
Added: Yes , not the best Vcc switch transistor used (higher saturation voltage).
Find transistor located more close to board center and marked 3F (BC857).
Replace it with BC807, marked 5C.
You can replace temporary it with standard package BC327.
Quote:
Error at 0x000043 Chip = 0xFF buffer = 0x42

In such failures you can repeat programming (overprogramming).
Only wrong programmed bits 0 cannot be repaired. Bits 1 can be programmed again without erase.
Try with increased twp from 1.2ms up to 2..3ms.
If failure remain Vcc performance should be improved.
-------
Another idea how to increase Vcc. Programmer has Vcc 5.6V and 6.2V support. Normally 6.2 V is not available. You can set Vcc 6.2 V mode - drive voltage 5.0/5.6 switch Jp8  hook in middle (not up and not down). Check Vcc voltage changes in Test H/W mode.
------
Quote:
now the board use a normal 7805 instead of the little one
with power supply 8V original 78M05 can handle currents.

Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: asbesto - 2008-08-24 20:46:48

EZo wrote on 08/24/08 at 18:46:27:
Quote:
5.17 using 112 ohm (56+56 ).... 4.71V

Vcc drops significant !! It can cause a failure. I will check used transistors in programmer and will be back.
Added: Yes , not the best Vcc switch transistor used (higher saturation voltage).
Find transistor located more close to board center and marked 3F (BC857).
Replace it with BC807, marked 5C.
You can replace temporary it with standard package BC327.


Ah. OK. now the problem is ... where to find such a transistor! Here there are no hardware stores I will check on some board in our lab...

Quote:
Another idea how to increase Vcc. Programmer has Vcc 5.6V and 6.2V support. Normally 6.2 V is not available. You can set Vcc 6.2 V mode - drive voltage 5.0/5.6 switch Jp8  hook in middle (not up and not down). Check Vcc voltage changes in Test H/W mode.


I will try this!
thank you  - tomorrow I will try changing the transistor.

Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: EZo - 2008-08-24 20:57:38

Quote:
thank you   - tomorrow I will try changing the transistor.

Try first to increase voltage to 6.2v mode - read, info was added to my previous topic !

Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: asbesto - 2008-08-25 09:41:58

EZo wrote on 08/24/08 at 20:57:38:
Quote:
thank you   - tomorrow I will try changing the transistor.

Try first to increase voltage to 6.2v mode - read, info was added to my previous topic !



I tried. Nothing changes! I installed jumpers instead of switch, but this was unuseful

I ordered some transistors, hope this will solve ... the entire situation is becoming very annoying!

Also, how can we check if an EPROM is ok, or damaged by overvoltage?

Re: Willem PRO4 ISP? Help, can't program 2764 or 2

By: EZo - 2008-08-25 17:31:31

Quote:
Also, how can we check if an EPROM is ok, or damaged by overvoltage?

No experience on damaged chips, always right voltages used.
Damaged chips have higher currents and programmer voltages can drop during operations. Always error at the same adress. Loss of data (chip blank, read results after programming return all 0x00) and more.
Quote:
... the entire situation is becoming very annoying!

Skip your 27128 and try your 27128A devices (I hope not shocked with 21/25V).
Higher 6.2V selection  can compensate voltage drop on existing transistor switch.
Set 12.7V Vpp and 6.2V Vcc. In Test H/W
Place resistor 100 Ohm from ZIF32/32 to ground (load ~50mA). Measure voltage on ZIF32/32.
Place resistor 56 Ohm from ZIF32/32 to ground (load ~100mA). Measure voltage on ZIF32/32.
Place resistor 470 Ohm Ohm from ZIF32/1 to ground (load ~25 mA). Measure voltage on ZIF32/1.
Place resistor 270 Ohm from ZIF32/1 to ground (load ~45mA). Measure voltage on ZIF32/1.
Come back with results.
Try program UV erased 27128A. What results ?