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Is it possible to reprogram this chip?

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DerStrom8

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Good day, all!
I recently came across several of these chips:

chip.jpg

I googled the number (D27128A-2) and found the datasheet, which says it's a programmable chip. However, my question is would it be possible for a user (me) to program it, and if so, what software would be needed?
Thanks in advance!
Der Strom
 
Good day, all!
I recently came across several of these chips:

View attachment 49512

.



I googled the number (D27128A-2) and found the datasheet, which says it's a programmable chip. However, my question is would it be possible for a user (me) to program it, and if so, what software would be needed?
Thanks in advance!
Der Strom

Hi,
Its a 128K bit EPROM, organised as 8 bit wide and 16K byte long
You could make a PC parallel port driven prommer, it requires exposure to UV light [eraser] , the window is hidden under the label.

Eprom Programmer - Base Board


EDIT: Corrected eeprom to eprom

Had a Senior Moment.... "hangs head in shame" , I will go and do 100 push ups in the snow...........:eek:
 

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Last edited:
Yes, thank you AtomSoft ;)
 
Hi,
Its a 128K bit EEPROM

Bit of a typo Eric?.

It's an EPROM (not an EEPROM) very different things.

As to it's uses - mostly they were used for program storage on old microprocessor systems - they don't have a great deal of use these days.

EDIT: Embarassing typo corrected - see original below.
 
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Don't throw them out, though! You might be able to find someone to buy them who restores old systems (mainly old 8-bit era machines, especially arcade machines). While I have a ton of them already, if you want to get rid of them, PM me (or contact me thru my website), and maybe we could work a paypal exchange (depending on what you want for them).
 
Thanks, guys!
Thank you cr0sh for the offer, but I'm still trying to learn more about microcontrollers. I have not yet gotten any PICs, so I'm thinking I might like to learn more using these, since I have the chips and I have the parts to build the programmer (Thanks, Eric!) :)
Der Strom
 
DerStrom8,

Whilst that chip can be programmed it is not a microcontroller but just an EPROM. You will just be wasting your time making a programmer as the final chip will be of no use. Get some pics and use your time and effort learning how to use them.

Mike.
 
Oh, thanks, Mike. I guess I misunderstood what the chip could do.
I'm still planning on getting some PICs anyway, so you probably just saved me a lot of time and money :) Thanks!
Der Strom
 
DerStrom8,

Whilst that chip can be programmed it is not a microcontroller but just an EPROM. You will just be wasting your time making a programmer as the final chip will be of no use. Get some pics and use your time and effort learning how to use them.

Mike.

Mike what was them chips that could be programmed there something like EPROM. You hooked a slow clock to it and it would toggle it's pins by how you programmed it.
 
Burt, are you thinking of PALs or PLAs like a GAL16V8? I last used one of those about 20 years ago.

Mike.
 
I was thinking it was like 20 years ago I couldn't remember what they where I found the site now lol **broken link removed**
 
Thanks, guys!
Thank you cr0sh for the offer, but I'm still trying to learn more about microcontrollers. I have not yet gotten any PICs, so I'm thinking I might like to learn more using these, since I have the chips and I have the parts to build the programmer (Thanks, Eric!) :)
Der Strom

hi,
If you can get 8255A IC's you can use the PC port to make a nice prommer, use LM317's for the Vd and Vpp switching

One application for these old EPROM's is binary to BCD converters or simple programmable logic
 
hi,
If you can get 8255A IC's you can use the PC port to make a nice prommer, use LM317's for the Vd and Vpp switching

8255's are absolutely horrible IC's, probably the poorest designed PIA chips made, yet people seem to still keep using them?.

One application for these old EPROM's is binary to BCD converters or simple programmable logic

Yes, a simple look-up table.
 
When I used some 8255s, about 20 years ago, they didn't strike me as particularly bad. Can you tell us what was wrong with them?

Is it just that there are better chips now?

No, there were far better chips back then - they were so limited - only certain modes and operations were allowed. Other chips, such as the 6522, were far more versatile.
 
It looks like your coding a shift register D0 D1 D3 D4 you set all that for input or output don't want none of that LOL

**broken link removed**
 
Got to agree with Nigel, the 8255s were pretty horrid.

Mike.

G'day Mike, Prosperous 2011...:)

I have used the 8255A in many designs and products with virtually no problems.

Its unlike you to use descriptors like 'pretty horrid' , usually you present a logical argument.

I would be interested to know the problems you encountered with the 8255A.

Regards
 
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