I could definitely help Steve out there Mike,  I still have 3 boards available, 
with parts to add pins and socket (optional).

Bill Nobel
b_nobel@ <mailto:[email protected]>hotmail.com



> On May 9, 2016, at 3:09 PM, Mike Stein <[email protected]> wrote:
> 
> Option 1: Buy a REX module. I'm not sure whether they're still available 
> through Club100 or you order them direct from Steve these days; I'm sure Ken 
> or Steve will log in and clarify.
>  
> Option 2: If you just want to replace the System ROM in a *NEW* M100 (or 
> don't mind unsoldering the original ROM in a T102) then all you need is a 
> 27C256 like the one below at jameco.
>  
> Option 3: If you want to replace the System ROM in an *OLD* M100 and/or add 
> an Option ROM to an old or new M100 then you'll need an adapter. If you're 
> only replacing the System ROM then a 27C256 is all you need; if you're adding 
> an Option ROM then you'll need a 27C512.
>  
> If you're up to assembling the adapter yourself then you can buy 6 bare 
> boards for $20 at Oshpark:
> https://www.oshpark.com/shared_projects/Kil9S1ya 
> <https://www.oshpark.com/shared_projects/Kil9S1ya>
>  
> You might want to read:
> http://bitchin100.com/wiki/index.php?title=M100ROM 
> <http://bitchin100.com/wiki/index.php?title=M100ROM>
>  
> You might also want to read the thread about Bill Nobel recently doing what 
> you want to do in the Bitchin100 archive, March and April; maybe you and he 
> can even get together off-list.
>  
> Maybe he has a spare board that he can sell you; if not, I could probably 
> come up with one.
>  
> m
>> ----- Original Message ----- 
>> From: Steven Ranft <mailto:[email protected]>
>> To: Club 100 Model T <mailto:[email protected]>
>> Sent: Monday, May 09, 2016 4:22 PM
>> Subject: Re: [M100] ROM burning questions
>> 
>> Hi  Mike,
>> I would like to replace my system ROM with a Y2K compatible version.
>> I would like to install the best single option ROM I can.
>> Would this chip work?
>> EPROM 256K-Bit 32K x 8 250ns 28-Pin DIP
>> http://www.jameco.com/1/1/2864-27c256-25-27c256-eprom-256k-bit-32k-x-8-250ns-28-pin-dip-memory.html
>>  
>> <http://www.jameco.com/1/1/2864-27c256-25-27c256-eprom-256k-bit-32k-x-8-250ns-28-pin-dip-memory.html>
>> 
>> Does anyone know where can I buy the adapter board for the ROM Socket?
>> 
>> Steve Ranft 
>> 
>> Savage, MN
>> 
>> 
>> From: [email protected]
>> To: [email protected]
>> Date: Mon, 9 May 2016 15:25:26 -0400
>> Subject: Re: [M100] ROM burning questions
>> 
>> Hi Steve,
>>  
>> Where to begin...
>>  
>> First of all, you're talking about two different and separate ROMs and their 
>> sockets, the System ROM which runs the computer and provides the various 
>> built-in applications, and an Option ROM which, as the name suggests, adds 
>> one or more optional programs or features. They are both 28-pin 32KB (256Kb) 
>> chips, so your 32-pin 128KB 27C010 chips will not fit without major 
>> adaptation.
>>  
>> As you (re)discovered regarding North American models, early M100s (prior to 
>> late 1983) used a non-standard pinout while later M100s and the T102, T200 
>> etc. used standard 27C256-compatible ROMs; the change seems to have been 
>> made somewhere between serial numbers 309xxxxxx and 401xxxxxx.
>>  
>> If you want to replace an early M100 System ROM you will have to make or buy 
>> an adapter; a fellow list member just built some using this board:
>> https://www.oshpark.com/shared_projects/Kil9S1ya 
>> <https://www.oshpark.com/shared_projects/Kil9S1ya>
>> Replacing a later model M100 System ROM is just a matter of plugging it in, 
>> but in the T102 it is soldered to the board and would require unsoldering 
>> the original ROM.
>>  
>> The Option ROMs use a completely different socket arrangement, a Molex IC 
>> 'carrier' with non-standard pinout but you can use the adapter above which 
>> lets you combine the System and Option ROM in one chip that plugs into the 
>> System ROM socket (old or new). At one time there was an adapter available 
>> from several sources that would let you put an OTP (not re-programmable) 
>> EPROM into the option ROM socket but they seem to not be available any 
>> longer.
>>  
>> Most people use Steve Adolph's REX module, which lets you put several 
>> different ROM images into one flash memory and I believe the later versions 
>> also permit changing the System ROM; see:
>> http://bitchin100.com/wiki/index.php?title=Rex 
>> <http://bitchin100.com/wiki/index.php?title=Rex>
>>  
>> Another very useful add-on is/was the NADSbox but I believe they're no 
>> longer available unless you find a used one; a newer version may or may not 
>> become available in the future.
>>  
>> Can't really give you a step-by-step since I don't know exactly what you 
>> want to do with/to what.
>>  
>> Good luck!
>>  
>> m
>>  
>>  
>> ----- Original Message ----- 
>>> From: Steven Ranft <mailto:[email protected]>
>>> To: Club 100 Model T <mailto:[email protected]>
>>> Sent: Monday, May 09, 2016 11:32 AM
>>> Subject: [M100] ROM burning questions
>>> 
>>> I am pretty new to retro computing. But have become an addict in the last 
>>> year or so.
>>> 
>>> I have Several M-100, M-102, M-200, NEC-8201 and NEC-8300 systems in 
>>> working order. I also have a ROM Booster PAC.
>>> 
>>> I really have only scratched the surface of learning to use these machines. 
>>> 
>>> I bought some "D43256AC-10L" chips and increased the Ram to 32 K on the 
>>> ones I could.
>>> 
>>> I managed to get  Virtual T running on my Windows 7 desktop. 
>>> 
>>> I built a cable, and can connect and transfer files to and from a laptop 
>>> running DOS via desklink
>>> 
>>> I also bought a Tandy floppy drive and got that working too.
>>> 
>>> I haven't yet tried to use the BoosterPAK
>>> 
>>> I did buy a e-prom burner (USB MiniPro TL866CS Universal BIOS Programmer) 
>>> and some blank e-proms (27C010-12 
>>> <https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_74624_-1>),
>>>  but HAD come to the conclusion that the M100s will not accept Standard 
>>> ROMs.
>>> 
>>> I found a file named What ROM.txt (... AND NOW know that was not accurate)
>>> 
>>> it has a section like this:
>>> 
>>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>> Board Code ROM type ROM Code Comment
>>> ==============================================================================
>>> PLX110CH1X custom LH535618 early North America
>>> PLX110EH1X 27C256 compatible 3256C07-3J1 late North America
>>> PLX120CH1X 27C256 compatible 3256C05-3E1 European/Italian
>>> I did a quick survey of serial numbers vs. PCB code and here are the 
>>> results.
>>> Generally, later serial numbers use the 27C256 compatible board.
>>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>> 
>>> I forgot about this information and just found it again. I have 102s and a 
>>> 200 to try, and probably several of 5 M-100s.
>>> 
>>> I am tempted to try to burn SARDOS and try to plug it in. I know i need to 
>>> run a BASIC command to "jump to an address" to get it to use the new ROM.
>>> 
>>> Does anybody know if there is a step by step "How to guide" for what I am 
>>> going to attempt and if not, do you have any words of wisdom or warnings?
>>> 
>>> I am pretty sure the "27C010-12 
>>> <https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_74624_-1>"
>>>  are "27C256" compatible chips or will find some, and I know to check the 
>>> serial number list and that there are different versions of SARDOS for the 
>>> various flavors of Model-T.
>>> 
>>> Anything I am missing?
>>> 
>>> I hope to create a document to guide other neophyte Model-T'ers through 
>>> this an post it on the repository if I get through it!
>>> 
>>> Thanks,
>>> 
>>> 
>>> Steve Ranft 
>>> 
>>> Savage, MN

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