Re: PROMs and EPROMs, specifically 2332/2532/2732

[Adrian Graham]

On 26/10/2015 17:09, "John Robertson"  wrote:


> Hi Adrian,
> 
> Perhaps one final test for your 2332s is to do a Diode Test on the pins
> relative to the ground pin (pin 12) and Vcc pin (24). These should sow
> either open or something like 0.6 or higher voltage drop across the pins
> - exchange the probes to check both directions.

I'll make up a small wiring harness that'll let me do that, it'll give me
something to do while I'm waiting for my lady to ring :)
 
> If your gates all read OK (check between Vcc and GND as well!), then it
> might be that the brand of 2332 you have simply draws more current than
> your programmer likes. What brand is the PROM? Perhaps it is in one of
> our reference book libraries...

They're all stock MOS 2332 PROMs used in every CBM PET. Mike's already
linked to the archive and tonight I've successfully burnt the 8032-flavour
PETTEST.BIN so my programmer is happy with Ti 2532JL EEPROMS that I
liberated from work.
 
Cheers,

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: PROMs and EPROMs, specifically 2332/2532/2732

[Mike Stein]

PET ROMs archive here:
http://www.zimmers.net/anonftp/pub/cbm/firmware/computers/pet/index.html


- Original Message - 
From: "John Robertson" <j...@flippers.com>
To: "General Discussion: On-Topic and Off-Topic 
Posts" <cctalk@classiccmp.org>

Sent: Monday, October 26, 2015 1:09 PM
Subject: Re: PROMs and EPROMs, specifically 
2332/2532/2732




On 10/25/2015 4:37 PM, Adrian Graham wrote:
On 25/10/2015 17:19, "John Robertson" 
<j...@flippers.com> wrote:



Hi John and others,

Thanks for that. I removed the diodes and 
wired 2332 (21) to 2372 (24)
leaving the A11 swap in place, the programmer 
complained about pin 18
missing. The adapter in front of me is now 
wired like this:


2332 (18) to 2372 (21)
2332 (20) 2x diodes to 2372 18 (band) and 20 
(band)

2332 (20) 2k2 resistor to 2332 (24)
2332 (21) to 2372 (24)

Now I get "reverse insertion" hinting I've 
wired something upside-down which
isn't the case. I can read 27256 and 2764's 
no problem so I'm mounting

things the correct way.

Further digging into available eproms that 
the programmer can read reveals
it CAN read 2532s, specifically the MCM2532 
which the datasheet tells me has
the same pinout as the 2332. I still get 
"reverse insertion error" so I'm

guessing my PROMs are toast.

Cheers,

Reverse insertion may just mean you are 
drawing more current on the /OE

and /CS than expected.

How about this - go back to my original 
suggestion (no diodes) and this
time add a small resistor to the 2732 pin 18 
and Vcc to act as a load.
Try larger resistors if the reader still 
complains - and try reading
with NO 2332 in the reader (all FFs). Once you 
can trick the reader into
reading air as highs then try your 2332 again 
with the working resistor

values for the unused select.

Oh, and what reader are you using? Did you 
check with the manufacturer
(or archives somewhere - archive.org?) to see 
if they have a trick for

reading 2532/2332s?
It's an MQP Pinmaster48, a 90s-era programmer. 
As it happens tonight I got
round to dumping some other EPROMs I had for 
someone else and one of them
was an SGS2532 which read fine as an MCM2532 so 
I know the machine works
with that age of chip. All my CBM ones give the 
same results so I'm assuming
they're dead. Thinking about it there may be 
some 2532s at work so I can try

burning a PET tester.

I saw the madrigaldesign adapter on Friday but 
after re-re-remaking the one
I was working on yesterday it was beginning to 
look a bit rough around the

edges :)

Cheers,


Hi Adrian,

Perhaps one final test for your 2332s is to do a 
Diode Test on the pins relative to the ground 
pin (pin 12) and Vcc pin (24). These should sow 
either open or something like 0.6 or higher 
voltage drop across the pins - exchange the 
probes to check both directions.


If your gates all read OK (check between Vcc and 
GND as well!), then it might be that the brand 
of 2332 you have simply draws more current than 
your programmer likes. What brand is the PROM? 
Perhaps it is in one of our reference book 
libraries...


If your 2332s are bad, then have you put out a 
call to see if anyone else has archived them 
already?


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, 
Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, 
Jukes, VideoGames)

 www.flippers.com
"Old pinballers never die, they just flip out"

Re: PROMs and EPROMs, specifically 2332/2532/2732

[John Robertson]

On 10/25/2015 4:37 PM, Adrian Graham wrote:

On 25/10/2015 17:19, "John Robertson"  wrote:


Hi John and others,

Thanks for that. I removed the diodes and wired 2332 (21) to 2372 (24)
leaving the A11 swap in place, the programmer complained about pin 18
missing. The adapter in front of me is now wired like this:

2332 (18) to 2372 (21)
2332 (20) 2x diodes to 2372 18 (band) and 20 (band)
2332 (20) 2k2 resistor to 2332 (24)
2332 (21) to 2372 (24)

Now I get "reverse insertion" hinting I've wired something upside-down which
isn't the case. I can read 27256 and 2764's no problem so I'm mounting
things the correct way.

Further digging into available eproms that the programmer can read reveals
it CAN read 2532s, specifically the MCM2532 which the datasheet tells me has
the same pinout as the 2332. I still get "reverse insertion error" so I'm
guessing my PROMs are toast.

Cheers,


Reverse insertion may just mean you are drawing more current on the /OE
and /CS than expected.

How about this - go back to my original suggestion (no diodes) and this
time add a small resistor to the 2732 pin 18 and Vcc to act as a load.
Try larger resistors if the reader still complains - and try reading
with NO 2332 in the reader (all FFs). Once you can trick the reader into
reading air as highs then try your 2332 again with the working resistor
values for the unused select.

Oh, and what reader are you using? Did you check with the manufacturer
(or archives somewhere - archive.org?) to see if they have a trick for
reading 2532/2332s?

It's an MQP Pinmaster48, a 90s-era programmer. As it happens tonight I got
round to dumping some other EPROMs I had for someone else and one of them
was an SGS2532 which read fine as an MCM2532 so I know the machine works
with that age of chip. All my CBM ones give the same results so I'm assuming
they're dead. Thinking about it there may be some 2532s at work so I can try
burning a PET tester.

I saw the madrigaldesign adapter on Friday but after re-re-remaking the one
I was working on yesterday it was beginning to look a bit rough around the
edges :)

Cheers,


Hi Adrian,

Perhaps one final test for your 2332s is to do a Diode Test on the pins 
relative to the ground pin (pin 12) and Vcc pin (24). These should sow 
either open or something like 0.6 or higher voltage drop across the pins 
- exchange the probes to check both directions.


If your gates all read OK (check between Vcc and GND as well!), then it 
might be that the brand of 2332 you have simply draws more current than 
your programmer likes. What brand is the PROM? Perhaps it is in one of 
our reference book libraries...


If your 2332s are bad, then have you put out a call to see if anyone 
else has archived them already?


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

RE: PROMs and EPROMs, specifically 2332/2532/2732

[tony duell]

> Further digging into available eproms that the programmer can read reveals
> it CAN read 2532s, specifically the MCM2532 which the datasheet tells me has
> the same pinout as the 2332. I still get "reverse insertion error" so I'm
> guessing my PROMs are toast.

As others have said, normally when putting a smaller chip into a programmer
with a bigger socket you keep the 'bottom row' of pins -- including ground --
in the same position for all chips. A look at the pinouts will show why. But as 
you can read 2716s that's not the problem.

Often 'reverse insertion error' means the chip drew the wrong supply current --
often far too much. Which does suggest your ROMs  are dead :-(

-tony

Re: PROMs and EPROMs, specifically 2332/2532/2732

[Adrian Graham]

On 25/10/2015 08:27, "tony duell"  wrote:

>> Further digging into available eproms that the programmer can read reveals
>> it CAN read 2532s, specifically the MCM2532 which the datasheet tells me has
>> the same pinout as the 2332. I still get "reverse insertion error" so I'm
>> guessing my PROMs are toast.
> 
> As others have said, normally when putting a smaller chip into a programmer
> with a bigger socket you keep the 'bottom row' of pins -- including ground --
> in the same position for all chips. A look at the pinouts will show why. But
> as 
> you can read 2716s that's not the problem.
> 
> Often 'reverse insertion error' means the chip drew the wrong supply current
> --
> often far too much. Which does suggest your ROMs  are dead :-(

Ah, OK, that makes sense. Bad ROMs and low-quality sockets are the chief
reasons for dying PETs so it doesn't surprise me. I've found some 2532s
pretty locally so hopefully they'll be with me on Tuesday and I can test
yesterday's soldering.

Wish there was a more local hobby/electronic shop here - I miss being in a
city but only for that reason :) Given that there are schematics for PET
testing boards like the PETVET I'd like to build my own. Nearest component
place is M*plins and they're not what they used to be.

Cheers!

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: PROMs and EPROMs, specifically 2332/2532/2732

[Adrian Graham]

On 25/10/2015 02:19, "Mike Stein"  wrote:

> Probably a silly question, but I assume that if
> you're using a 28-pin socket you are inserting it
> aligned at the end *opposite* pin 1, with pin
> numbers offset by 2 (ie. 2x32 pin1 is 2764/256 pin
> 3, etc.)?
> 

Hi Mike,

Yes :) 

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: PROMs and EPROMs, specifically 2332/2532/2732

[Adrian Graham]

On 25/10/2015 17:19, "John Robertson"  wrote:

>> Hi John and others,
>> 
>> Thanks for that. I removed the diodes and wired 2332 (21) to 2372 (24)
>> leaving the A11 swap in place, the programmer complained about pin 18
>> missing. The adapter in front of me is now wired like this:
>> 
>> 2332 (18) to 2372 (21)
>> 2332 (20) 2x diodes to 2372 18 (band) and 20 (band)
>> 2332 (20) 2k2 resistor to 2332 (24)
>> 2332 (21) to 2372 (24)
>> 
>> Now I get "reverse insertion" hinting I've wired something upside-down which
>> isn't the case. I can read 27256 and 2764's no problem so I'm mounting
>> things the correct way.
>> 
>> Further digging into available eproms that the programmer can read reveals
>> it CAN read 2532s, specifically the MCM2532 which the datasheet tells me has
>> the same pinout as the 2332. I still get "reverse insertion error" so I'm
>> guessing my PROMs are toast.
>> 
>> Cheers,
>> 
> 
> Reverse insertion may just mean you are drawing more current on the /OE
> and /CS than expected.
> 
> How about this - go back to my original suggestion (no diodes) and this
> time add a small resistor to the 2732 pin 18 and Vcc to act as a load.
> Try larger resistors if the reader still complains - and try reading
> with NO 2332 in the reader (all FFs). Once you can trick the reader into
> reading air as highs then try your 2332 again with the working resistor
> values for the unused select.
> 
> Oh, and what reader are you using? Did you check with the manufacturer
> (or archives somewhere - archive.org?) to see if they have a trick for
> reading 2532/2332s?

It's an MQP Pinmaster48, a 90s-era programmer. As it happens tonight I got
round to dumping some other EPROMs I had for someone else and one of them
was an SGS2532 which read fine as an MCM2532 so I know the machine works
with that age of chip. All my CBM ones give the same results so I'm assuming
they're dead. Thinking about it there may be some 2532s at work so I can try
burning a PET tester.

I saw the madrigaldesign adapter on Friday but after re-re-remaking the one
I was working on yesterday it was beginning to look a bit rough around the
edges :)

Cheers,

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: PROMs and EPROMs, specifically 2332/2532/2732

[John Robertson]

On 10/24/2015 5:56 PM, Adrian Graham wrote:



On 24/10/2015 19:18, "John Robertson"  wrote:


On 10/24/2015 5:43 AM, Adrian Graham wrote:

Hi folks,

PET4032 repair continues with all ROMs, video RAM and dodgy sockets removed
thanks to a hot air gun. Holes cleaned and I have new turned pin sockets for
everything I've removed which I'll be fitting this afternoon.

Since the ROMs came out OK I'm trying to dump them using my Pinmaster48
programmer, being from the 90s it doesn't read 2332/2532 PROMs but it WILL
read a lot of variants of 2732 so I've made an adapter as found thanks to
google and USENET:

2332 pin 18 to 2732 pin 21 (A11)
2332 pin 20 to 2732 pin 18 (Chip enable/Power Down)
2332 pin 21 to 2732 pins 20 and 24 via diodes with banding at the 2332 end
(2332 Vpp)

Wiring checks out and the diodes are aligned correctly so pins 20 and 24
don't interfere with each other, however the pinmaster continually gives me
"continuity error on pin 20"

Have I goofed somewhere?

Cheers,


You just tie pin 21 of the 2332 to Vcc (+5) - Pin 24 of the 2732 - to read.

There are only two modifications needed normally for reading a 2532/2332
in a 2732 socket.

2332

Pin 21 - Vcc (2732 Pin 24)
Pin 18 - A11 (2732 Pin 21)

If your reader coughs up a /OE error then use diodes:

2332

Pin 20 - 2 Diodes, one to 2732 pin 20, the other to 2732 pin 18. Banded
end to these pins, and you will also need a pullup resistor on the
2532/2332 socket pin 20 so /CE (2332/2532) goes high when not selected.
2K2 would do fine. Anything from your junk box between 1K and 4K7 should
work though.

I don't think you will need the diodes though.

John :-#)#

Hi John and others,

Thanks for that. I removed the diodes and wired 2332 (21) to 2372 (24)
leaving the A11 swap in place, the programmer complained about pin 18
missing. The adapter in front of me is now wired like this:

2332 (18) to 2372 (21)
2332 (20) 2x diodes to 2372 18 (band) and 20 (band)
2332 (20) 2k2 resistor to 2332 (24)
2332 (21) to 2372 (24)

Now I get "reverse insertion" hinting I've wired something upside-down which
isn't the case. I can read 27256 and 2764's no problem so I'm mounting
things the correct way.

Further digging into available eproms that the programmer can read reveals
it CAN read 2532s, specifically the MCM2532 which the datasheet tells me has
the same pinout as the 2332. I still get "reverse insertion error" so I'm
guessing my PROMs are toast.

Cheers,



Reverse insertion may just mean you are drawing more current on the /OE 
and /CS than expected.


How about this - go back to my original suggestion (no diodes) and this 
time add a small resistor to the 2732 pin 18 and Vcc to act as a load. 
Try larger resistors if the reader still complains - and try reading 
with NO 2332 in the reader (all FFs). Once you can trick the reader into 
reading air as highs then try your 2332 again with the working resistor 
values for the unused select.


Oh, and what reader are you using? Did you check with the manufacturer 
(or archives somewhere - archive.org?) to see if they have a trick for 
reading 2532/2332s?


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: PROMs and EPROMs, specifically 2332/2532/2732

[John Robertson]

On 10/24/2015 5:56 PM, Adrian Graham wrote:



On 24/10/2015 19:18, "John Robertson"  wrote:


On 10/24/2015 5:43 AM, Adrian Graham wrote:

Hi folks,

PET4032 repair continues with all ROMs, video RAM and dodgy sockets removed
thanks to a hot air gun. Holes cleaned and I have new turned pin sockets for
everything I've removed which I'll be fitting this afternoon.

Since the ROMs came out OK I'm trying to dump them using my Pinmaster48
programmer, being from the 90s it doesn't read 2332/2532 PROMs but it WILL
read a lot of variants of 2732 so I've made an adapter as found thanks to
google and USENET:

2332 pin 18 to 2732 pin 21 (A11)
2332 pin 20 to 2732 pin 18 (Chip enable/Power Down)
2332 pin 21 to 2732 pins 20 and 24 via diodes with banding at the 2332 end
(2332 Vpp)

Wiring checks out and the diodes are aligned correctly so pins 20 and 24
don't interfere with each other, however the pinmaster continually gives me
"continuity error on pin 20"

Have I goofed somewhere?

Cheers,


You just tie pin 21 of the 2332 to Vcc (+5) - Pin 24 of the 2732 - to read.

There are only two modifications needed normally for reading a 2532/2332
in a 2732 socket.

2332

Pin 21 - Vcc (2732 Pin 24)
Pin 18 - A11 (2732 Pin 21)

If your reader coughs up a /OE error then use diodes:

2332

Pin 20 - 2 Diodes, one to 2732 pin 20, the other to 2732 pin 18. Banded
end to these pins, and you will also need a pullup resistor on the
2532/2332 socket pin 20 so /CE (2332/2532) goes high when not selected.
2K2 would do fine. Anything from your junk box between 1K and 4K7 should
work though.

I don't think you will need the diodes though.

John :-#)#

Hi John and others,

Thanks for that. I removed the diodes and wired 2332 (21) to 2372 (24)
leaving the A11 swap in place, the programmer complained about pin 18
missing. The adapter in front of me is now wired like this:

2332 (18) to 2372 (21)
2332 (20) 2x diodes to 2372 18 (band) and 20 (band)
2332 (20) 2k2 resistor to 2332 (24)
2332 (21) to 2372 (24)

Now I get "reverse insertion" hinting I've wired something upside-down which
isn't the case. I can read 27256 and 2764's no problem so I'm mounting
things the correct way.

Further digging into available eproms that the programmer can read reveals
it CAN read 2532s, specifically the MCM2532 which the datasheet tells me has
the same pinout as the 2332. I still get "reverse insertion error" so I'm
guessing my PROMs are toast.

Cheers,


Oh, and here is what someone did in 2011 to read 2332s:

http://www.madrigaldesign.it/forum/viewtopic.php?t=104

John ;-#)#

PROMs and EPROMs, specifically 2332/2532/2732

[Adrian Graham]

Hi folks,

PET4032 repair continues with all ROMs, video RAM and dodgy sockets removed
thanks to a hot air gun. Holes cleaned and I have new turned pin sockets for
everything I've removed which I'll be fitting this afternoon.

Since the ROMs came out OK I'm trying to dump them using my Pinmaster48
programmer, being from the 90s it doesn't read 2332/2532 PROMs but it WILL
read a lot of variants of 2732 so I've made an adapter as found thanks to
google and USENET:

2332 pin 18 to 2732 pin 21 (A11)
2332 pin 20 to 2732 pin 18 (Chip enable/Power Down)
2332 pin 21 to 2732 pins 20 and 24 via diodes with banding at the 2332 end
(2332 Vpp)

Wiring checks out and the diodes are aligned correctly so pins 20 and 24
don't interfere with each other, however the pinmaster continually gives me
"continuity error on pin 20"

Have I goofed somewhere?

Cheers,

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: PROMs and EPROMs, specifically 2332/2532/2732

[John Robertson]

On 10/24/2015 5:43 AM, Adrian Graham wrote:

Hi folks,

PET4032 repair continues with all ROMs, video RAM and dodgy sockets removed
thanks to a hot air gun. Holes cleaned and I have new turned pin sockets for
everything I've removed which I'll be fitting this afternoon.

Since the ROMs came out OK I'm trying to dump them using my Pinmaster48
programmer, being from the 90s it doesn't read 2332/2532 PROMs but it WILL
read a lot of variants of 2732 so I've made an adapter as found thanks to
google and USENET:

2332 pin 18 to 2732 pin 21 (A11)
2332 pin 20 to 2732 pin 18 (Chip enable/Power Down)
2332 pin 21 to 2732 pins 20 and 24 via diodes with banding at the 2332 end
(2332 Vpp)

Wiring checks out and the diodes are aligned correctly so pins 20 and 24
don't interfere with each other, however the pinmaster continually gives me
"continuity error on pin 20"

Have I goofed somewhere?

Cheers,


You just tie pin 21 of the 2332 to Vcc (+5) - Pin 24 of the 2732 - to read.

There are only two modifications needed normally for reading a 2532/2332 
in a 2732 socket.


2332

Pin 21 - Vcc (2732 Pin 24)
Pin 18 - A11 (2732 Pin 21)

If your reader coughs up a /OE error then use diodes:

2332

Pin 20 - 2 Diodes, one to 2732 pin 20, the other to 2732 pin 18. Banded 
end to these pins, and you will also need a pullup resistor on the 
2532/2332 socket pin 20 so /CE (2332/2532) goes high when not selected. 
2K2 would do fine. Anything from your junk box between 1K and 4K7 should 
work though.


I don't think you will need the diodes though.

John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: PROMs and EPROMs, specifically 2332/2532/2732

[Adrian Graham]

On 24/10/2015 19:18, "John Robertson"  wrote:

> On 10/24/2015 5:43 AM, Adrian Graham wrote:
>> Hi folks,
>> 
>> PET4032 repair continues with all ROMs, video RAM and dodgy sockets removed
>> thanks to a hot air gun. Holes cleaned and I have new turned pin sockets for
>> everything I've removed which I'll be fitting this afternoon.
>> 
>> Since the ROMs came out OK I'm trying to dump them using my Pinmaster48
>> programmer, being from the 90s it doesn't read 2332/2532 PROMs but it WILL
>> read a lot of variants of 2732 so I've made an adapter as found thanks to
>> google and USENET:
>> 
>> 2332 pin 18 to 2732 pin 21 (A11)
>> 2332 pin 20 to 2732 pin 18 (Chip enable/Power Down)
>> 2332 pin 21 to 2732 pins 20 and 24 via diodes with banding at the 2332 end
>> (2332 Vpp)
>> 
>> Wiring checks out and the diodes are aligned correctly so pins 20 and 24
>> don't interfere with each other, however the pinmaster continually gives me
>> "continuity error on pin 20"
>> 
>> Have I goofed somewhere?
>> 
>> Cheers,
>> 
> You just tie pin 21 of the 2332 to Vcc (+5) - Pin 24 of the 2732 - to read.
> 
> There are only two modifications needed normally for reading a 2532/2332
> in a 2732 socket.
> 
> 2332
> 
> Pin 21 - Vcc (2732 Pin 24)
> Pin 18 - A11 (2732 Pin 21)
> 
> If your reader coughs up a /OE error then use diodes:
> 
> 2332
> 
> Pin 20 - 2 Diodes, one to 2732 pin 20, the other to 2732 pin 18. Banded
> end to these pins, and you will also need a pullup resistor on the
> 2532/2332 socket pin 20 so /CE (2332/2532) goes high when not selected.
> 2K2 would do fine. Anything from your junk box between 1K and 4K7 should
> work though.
> 
> I don't think you will need the diodes though.
> 
> John :-#)#

Hi John and others,

Thanks for that. I removed the diodes and wired 2332 (21) to 2372 (24)
leaving the A11 swap in place, the programmer complained about pin 18
missing. The adapter in front of me is now wired like this:

2332 (18) to 2372 (21)
2332 (20) 2x diodes to 2372 18 (band) and 20 (band)
2332 (20) 2k2 resistor to 2332 (24)
2332 (21) to 2372 (24)

Now I get "reverse insertion" hinting I've wired something upside-down which
isn't the case. I can read 27256 and 2764's no problem so I'm mounting
things the correct way.

Further digging into available eproms that the programmer can read reveals
it CAN read 2532s, specifically the MCM2532 which the datasheet tells me has
the same pinout as the 2332. I still get "reverse insertion error" so I'm
guessing my PROMs are toast.

Cheers,

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: PROMs and EPROMs, specifically 2332/2532/2732

[Mike Stein]

Probably a silly question, but I assume that if 
you're using a 28-pin socket you are inserting it 
aligned at the end *opposite* pin 1, with pin 
numbers offset by 2 (ie. 2x32 pin1 is 2764/256 pin 
3, etc.)?


m


- Original Message - 
From: "Adrian Graham" 
<wit...@binarydinosaurs.co.uk>
To: <j...@flippers.com>; "General Discussion: 
On-Topic and Off-Topic Posts" 
<cctalk@classiccmp.org>

Sent: Saturday, October 24, 2015 8:56 PM
Subject: Re: PROMs and EPROMs, specifically 
2332/2532/2732







On 24/10/2015 19:18, "John Robertson" 
<j...@flippers.com> wrote:



On 10/24/2015 5:43 AM, Adrian Graham wrote:

Hi folks,

PET4032 repair continues with all ROMs, video 
RAM and dodgy sockets removed
thanks to a hot air gun. Holes cleaned and I 
have new turned pin sockets for
everything I've removed which I'll be fitting 
this afternoon.


Since the ROMs came out OK I'm trying to dump 
them using my Pinmaster48
programmer, being from the 90s it doesn't read 
2332/2532 PROMs but it WILL
read a lot of variants of 2732 so I've made an 
adapter as found thanks to

google and USENET:

2332 pin 18 to 2732 pin 21 (A11)
2332 pin 20 to 2732 pin 18 (Chip enable/Power 
Down)
2332 pin 21 to 2732 pins 20 and 24 via diodes 
with banding at the 2332 end

(2332 Vpp)

Wiring checks out and the diodes are aligned 
correctly so pins 20 and 24
don't interfere with each other, however the 
pinmaster continually gives me

"continuity error on pin 20"

Have I goofed somewhere?

Cheers,

You just tie pin 21 of the 2332 to Vcc (+5) - 
Pin 24 of the 2732 - to read.


There are only two modifications needed 
normally for reading a 2532/2332

in a 2732 socket.

2332

Pin 21 - Vcc (2732 Pin 24)
Pin 18 - A11 (2732 Pin 21)

If your reader coughs up a /OE error then use 
diodes:


2332

Pin 20 - 2 Diodes, one to 2732 pin 20, the 
other to 2732 pin 18. Banded
end to these pins, and you will also need a 
pullup resistor on the
2532/2332 socket pin 20 so /CE (2332/2532) goes 
high when not selected.
2K2 would do fine. Anything from your junk box 
between 1K and 4K7 should

work though.

I don't think you will need the diodes though.

John :-#)#


Hi John and others,

Thanks for that. I removed the diodes and wired 
2332 (21) to 2372 (24)
leaving the A11 swap in place, the programmer 
complained about pin 18
missing. The adapter in front of me is now wired 
like this:


2332 (18) to 2372 (21)
2332 (20) 2x diodes to 2372 18 (band) and 20 
(band)

2332 (20) 2k2 resistor to 2332 (24)
2332 (21) to 2372 (24)

Now I get "reverse insertion" hinting I've wired 
something upside-down which
isn't the case. I can read 27256 and 2764's no 
problem so I'm mounting

things the correct way.

Further digging into available eproms that the 
programmer can read reveals
it CAN read 2532s, specifically the MCM2532 
which the datasheet tells me has
the same pinout as the 2332. I still get 
"reverse insertion error" so I'm

guessing my PROMs are toast.

Cheers,

--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest 
private home computer

collection?