Got a few ROMs programmed - finally

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ViperSan
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Got a few ROMs programmed - finally

Postby ViperSan » Sun Sep 10, 2017 3:45 am

The adapter bases I ordered from the USA finally arrived ..so figured I'd have a play with some 27C64s I had recovered and blanked with UV..this weekend.
Downloaded the bin images ..but wasn't sure my TL866 programmer was up to the job.
Well the 27C64 _is_ in the list ..but I'm sure is not natively supported ??
tried the kernal first which failed to program.
First on account the chip ID isn't recognised ..
luckilly there is a tick box option in the software to ignore the ID ..
..but still programming could not proceed beyond XX0F..
at least not with the default settings ..
Upping the pulse delay timing to 200us and the VPP (programming voltage) to 21v in the options..
..fixed this ..
All roms together tested on a recently repaired VIC20 board..which had faulty memory and a faulty 6522.
Sadly I have no case for this board so I will use it for Test and repair.
So now I could proceed to flash a CHAR and BASIC rom also.
Nice to have options.
rgds
VS
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Kakemoms
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Re: Got a few ROMs programmed - finally

Postby Kakemoms » Thu Sep 14, 2017 9:01 am

Nice work! If you have some larger EPROMs like 27C128 or alike, its possible to switch between different Kernals (like normal and Jiffydos) using a simple switch and pullup+pulldown resistors. :wink:

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Floopy
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Re: Got a few ROMs programmed - finally

Postby Floopy » Mon Sep 18, 2017 11:32 am

How do you build the adapter in order to use 27C* instead of 23C* ?
-Floopy

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srowe
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Re: Got a few ROMs programmed - finally

Postby srowe » Mon Sep 18, 2017 12:12 pm

Jim Brain sells some PCBs

http://store.go4retro.com/2364-adapter/

Alternatively you can build your own using the pinouts here

https://ist.uwaterloo.ca/~schepers/roms.html

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Floopy
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Re: Got a few ROMs programmed - finally

Postby Floopy » Mon Sep 18, 2017 4:23 pm

Also what size is usually required 8K, 16k, or 32k. I'm just getting started on doing custom rom's.
-Floopy

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Floopy
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Re: Got a few ROMs programmed - finally

Postby Floopy » Mon Sep 18, 2017 4:36 pm

Oops never mind I see that 8k is the standard, but I think that is cool that you can have two different memory banks in one chip.
Thanks you
-Floopy


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