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EPROM Emulator

PostPosted: Sun Oct 12, 2014 11:17 am
by SteveMoody
Hi,

I'm designing an EPROM emulator based on the design from Philip Pemberton here http://www.piclist.com/images/boards/EP ... /index.htm

Got a circuit drawn up for a circuit using USB rather than RS232. If anyone is interested i will share the design files here.

Re: EPROM Emulator

PostPosted: Sun Oct 12, 2014 11:20 am
by simon
Really nice, Steve. Thanks for sharing this! :thumbup:
What I wonder: Would it be hard to replace the PIC with an Atmega? Thus I would need only one Flash programmer and could re-use the Atmels which lay around here.

Re: EPROM Emulator

PostPosted: Sun Oct 12, 2014 11:47 am
by SteveMoody
It should be easy enough to replace the PIC. I've not looked into the code too much yet but I think it would be easy enough to reuse,

Re: EPROM Emulator

PostPosted: Tue Jan 06, 2015 12:53 am
by legacy
hi
i am interested, have you already completed the PCB file ?
what do you use ? EagleCAD ? OrCAD ?

Re: EPROM Emulator

PostPosted: Tue Jan 06, 2015 12:59 am
by legacy
also, how fast do you upload ? 1Mbps ?

about teensy, it seems able to go up to 1Mbps and more (without arduino/teensy library), but i have found this issue with UHCI on linux. Perfectly working with OHCI, also the problem seems related to the arduino/teensy library.

about "eprom emulators" i have opened this thread which has 2 projects that could help/inspire

Re: EPROM Emulator

PostPosted: Tue Jan 06, 2015 12:59 am
by SteveMoody
I've changed the design a bit since i last posted.

I'm planning on building a prototype before i progress any further.

Re: EPROM Emulator

PostPosted: Tue Jan 06, 2015 1:24 am
by legacy
what do you use about CAD ?

i am thinking about having something at 10Mbit/sec, there are commercial products that perform like that, basically ARM chip with a built-in USB2

Re: EPROM Emulator

PostPosted: Tue Jan 06, 2015 7:43 am
by simon
I use gEDA. I think you should start reading the website and forums. I could answer almost every of your questions with a link. ;)

10MBit/s what for? For a 32kb Eprom simulator? That makes as much sense as using a Ferrari to visit your neighbour. :lol:

Re: EPROM Emulator

PostPosted: Tue Jan 06, 2015 9:44 am
by SteveMoody
I use a package called Proteus for the CAD.

Why would you need something that fast for an EPROM emulator? Even running over a serial connection like in this design it will only take a few seconds to transfer the data to the board. Still much faster than burning an EPROM

Re: EPROM Emulator

PostPosted: Tue Jan 06, 2015 12:38 pm
by legacy
first of all the serial is not so good on linux, you have to deal with term/io2 (instead of term/io) if you got faster than 230400bps, it's not a problem but you have care about that if you use an abnormal serial device at 1Mbps which is the best you can have

btw 1Mbps is too slow for 512Kbyte of ram, it goes less than 100Kbyte/sec, so we are speaking about 5-6 seconds for the uploads
with 10Mbps (over ethernet, or over usb2), it's less than 1 second

it makes the differences if you do a lot of uploads in a day :D

also, in my home made 68k-board i have 512Kbyte of emulated rom, and i simply want a faster device!

p.s.
at the commercial side, it could be interesting for automotive applications