27C400/27C800 EPROM emulator

[cmorley]

What does Enable A19 do then? it seems redundant?

If you want to drive A19 from an external source you can. Most commonly would be a 32 bit set up where one module drives A18 & A19 and the other is driven externally from the "master" module.

Alternately you could drive it from some decoded logic (e.g. kick + extended ROM support from one module) or an external switch even.

[terriblefire]

Thanks.. i think this whole thing has way more features than i ever need.

Last question... do you have an automated script for updating the rom? its not a huge number of clicks but it adds up when you do it 3 times a minute.

[cmorley]

do you have an automated script for updating the rom?

If you've got a makefile (or batch build) then knock up a python (other scripting languages are available) script to open the serial port, send the commands & send the binary as part of a make & send recipe/target. You can silently eat all the data returned by the module or copy it to the console.

Once working you've got total flexibility and control over the module including driving the GPIO and ROM switching via USB.

Or... make a .cmd file along the lines of:

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echo|set /p="op1mfc^" > pgm.txt
echo|set /p="p02y" >> pgm.txt
type kick13.rom >> pgm.txt
echo|set /p="p15n" >> pgm.txt
type kick314.bin >> pgm.txt
echo|set /p="p25y" >> pgm.txt
type kick31.rom >> pgm.txt
echo|set /p="p35n" >> pgm.txt
type 16bit.bin >> pgm.txt
echo|set /p="i" >> pgm.txt

and use the send binary file from your terminal program to send pgm.txt. If using linux then a bash script equivalent.

In the example I set the options first, then program 4 kick images. You can put anything in there.

I know a couple of people who have scripted the module as part of a build environment. It works well apparently but I don't have an example script...
edit: example python script https://github.com/keirf/Amiga-Stuff/bl ... /boobip.py

[terriblefire]

Perfect thanks. .

In my use cases i never do rom switching. I'm really just interested in fast rom updates. i would have happily taken a board with jumpers on it for switching.

[gtfan]

Given the correct adapter electrically it should work. You'd need to tie the unused address lines to ground because 27C1024 is 64Kx16 and 27C200 (smallest EPROM my thing supports) is 128Kx16.

Adapting a DIP to a PLCC socket is a pain though - the other way round is a lot easier.

None of the parts on it are automotive grade for temperature or vibration. (e.g. no flexible MLCC caps) You could maybe use it for dyno work but not in a car on the public road.

Thanks for reply. Taking the above into account I will pass on that idea.

[rosewood]

I'm using this emulator to program/switch the system ROMs of my Philips CD-i players. It takes ~6 seconds to program a ROM and is way faster than a regular EPROM program and erase cycle.

DSC_4645.jpg

[trixster]

I thought I’d post to say that these eprom emulators have been great for use in testing different Amiga kickstart roms with DSP compatibility, so thanks again cmorley

588A35A5-3DB3-4DE4-B2CB-68D685F0F531.jpeg

[patracy]

So I'd like a second set of eyes before I toss this in the amiga 2000. I've transferred diagrom and KS3.1.4 to it in bank 0 and 1 respectively. I am intentionally wanting this to run via a hard switch and not via the reset signal. (I have a accelerator and it's been a bear to get working with a romulator) I guess I'm missing it, but how does one specify what A18 and A19 select? I know that initial rom is set at 0 (diagrom).

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****************************************************************
BooBip 27C200/400/800/160 EPROM emulator & ROM switcher
www.BooBip.com

Device          18.011 issue C/D
STM32 firmware  0.8 (C)2020 Chris Morley
CPLD firmware   0.10 (C)2020 Chris Morley
Firmware CRC    bc177c4d
STM32 id        dev=0x445, rev=0x1000
STM32 uid       002e001c 544d4305 20313330
CPLD id         mfg=0x06e, dev=0x20a5, rev=0
FLASH id        mfg=1, dev=0xc4
EPROM type      27C400 (512KB)
ROM selected    0

Acknowledgements
Clifford Wolf. Lib(X)SVF:
  A library for implementing SVF and XSVF JTAG players.
  http://www.clifford.at/libxsvf/

And here's the options:

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 >option menu
                    A17 A18 A19
pull-up              n   y   y
enable               n   y   y
ROM size            27C400 512KB
intial ROM          0
autosave initial    n
ROM switch pullup   y
wireless ROM switch n
enable LED          y
USB                 FACTORY

[cmorley]

So I'd like a second set of eyes before I toss this in the amiga 2000. I've transferred diagrom and KS3.1.4 to it in bank 0 and 1 respectively. I am intentionally wanting this to run via a hard switch and not via the reset signal. (I have a accelerator and it's been a bear to get working with a romulator) I guess I'm missing it, but how does one specify what A18 and A19 select? I know that initial rom is set at 0 (diagrom).

If you've programmed 0 & 1 then a toggle switch between A18 and ground will switch between the two images. You need to turn off the enable on A18 though or the STM32 will try to drive it. Leave it on for A19 so it pulls that low for you.

(You can get more sophisticated with 4 images or 1024KB images later)

[cmorley]

amiga 2000.

What revision A2000 have you got?

I checked my rev 6.2 A2000 motherboard & it uses the standard JEDEC ROM pinout. Pin31 is connected to VCC.

The rev 6 schematics in the A500/2000TRM show pin31->A18 which is the non-JEDEC commodore pinout of the rev3 & 5 A500.

So if your ROM pin 31 is connected to A18 (pin 46 CPU) then you will need to solder the /JEDEC (not JEDEC) jumper to swap the module pinout.