Author Topic: looking for a rom/ram emulator  (Read 15442 times)

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Offline marmad

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Re: looking for a rom/ram emulator
« Reply #25 on: November 04, 2014, 08:54:22 pm »
Just saw this thread, so I don't know if you've already bought a Moates or built something. It's been awhile since I needed to emulate parallel EPROM/RAM chips, but I need to do it again for some old devices, so I'm throwing together some parts to hack onto an old Xeltek programmer.

If you just need emulation but don't really require complex tracing (which, for me, is the majority of the time), it's quite easy to turn any existing USB EPROM programmer into an emulator for a couple of bucks worth of parts and a couple of hours of time; this allows you to skip both spending much time on hardware as well as having to develop any software. If you want to get clever, you can tap into some of the programmer's routines to simulate some trace-like features.
 

Online marshallh

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Re: looking for a rom/ram emulator
« Reply #26 on: November 05, 2014, 02:04:40 am »
Cyclone III + 2mbit SRAM + FT245?
Verilog tips
BGA soldering intro

11:37 <@ktemkin> c4757p: marshall has transcended communications media
11:37 <@ktemkin> He speaks protocols directly.
 

Offline solac

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Re: looking for an rom/ram emulator
« Reply #27 on: October 05, 2015, 04:20:37 am »


Around the CPU/whatever you need to isolate the eprom/ram to the target socket. Just a bit of 245 buffer arounds.

Btw, i have found this project that clarifies the concept. This project seems in use for something that deals with [i[pimp my ride car tuning[/i], also is seems using the same protocol used by Ostrich V2, which is a good points for its firmware. His authors claimed a "an ugly buy" somewhere in the circuit, be careful about that  :-//

hi sorry to revive and old thread. i was wondering if anyone has built this using the schematics ?
 

Offline commie

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Re: looking for a rom/ram emulator
« Reply #28 on: October 05, 2015, 10:13:24 pm »
I bought this about year ago, used it once with success so far as I remember. Emulates up to 512k bytes roms.

http://uk.mouser.com/ProductDetail/EETools/EEROM-8U/?qs=%2fha2pyFadujQ4oaad2MGF7AB4v%252bBJJb9qocvcQuRPzaBOuwuz7FGwzIv3GOkcmmY
 

Offline free_electron

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Re: looking for a rom/ram emulator
« Reply #29 on: October 05, 2015, 11:02:02 pm »
What protocol ? its a ram / eprom emulator. it emulates the classic static rams and parallel e/eeproms.
it can also dump the ram content and inverse assemble.

launch setup.exe. has really neat software.
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Offline commie

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Re: looking for a rom/ram emulator
« Reply #30 on: October 06, 2015, 11:12:08 am »
c'on man, the USB protocol !!! I neet to attach it to a Linux/MIPS SoC, there is no Windows/x86 inside

Sorry Legacy, I'm using Windows XP and it works with that, but I do not know whether it will work with Linux.

It has the capacity to go to 1Megbyte but you need a special adapter, with the adapters supplied , 512kbyte max.
 

Offline free_electron

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Re: looking for a rom/ram emulator
« Reply #31 on: October 06, 2015, 08:30:11 pm »
What protocol ? its a ram / eprom emulator

c'on man, the USB protocol !!! I neet to attach it to a Linux/MIPS SoC, there is no Windows/x86 inside
does that matter ? the target system is irrelevant. if your MIPS machine has a socket for an Eprom it will work. the OS / CPU doesn't matter.
the emulator has a ram on board with some logic that makes it behave as an eprom. Load the image into the emulator and your MIPS machine is none the wiser. it doesn;t need access to USB. the USB port is for the host machine where you run the development environment.

Oh , wait .. you mean : you want to use this on a MIPS based machine using linux , cause that is your development box ? tough shit sherlock.  The prevalent dev hardware is a intel architecture running microsoft stuff. once in a while you may find some linux stuff on intel. But beyond that ? it's a VERY small world.... Things are developed for the market. like it or not , that is still 90% Wintel ...and a bit Lintel and maybe a tiny bit iOS. anything else is esoteric and you will have to resort to homebrew.

Elektor magazine made an eprom emulator in the mid 90's that was using a 62256 ram , some counters and hooked up to a standard printerport.
you would take the binary image of the rom and simply 'copy' it to LPT1.

you had to press a button on the emulator to 'reset it'. you could then simply use a dos command 'copy eprom.bin lpt1:' and that was it.
they later made an rs232 version

https://www.elektormagazine.com/magazine/elektor-200101/16948

https://www.elektormagazine.com/magazine/elektor-200101

with any luck you can still buy the circuit board. a few dollar for the PDF file and off you go. that may be your best shot.

here's another one (older) : http://www.davidprojects.net78.net/styled-2/index.html

i built several of the printerport ones. they were mades using SMd and used 74590 and 74593 dual counters that were expensive and hard to find at the time.



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Offline solac

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Re: looking for a rom/ram emulator
« Reply #32 on: October 07, 2015, 12:46:18 am »
Im no engineer, nor do i understand how code work. Was looking to build this for personal use. I have seen this device demonstration in youtube. It used xtronics protocol to connect to crome. I was wondering if the hex file in the hub works? If i could i would just buy a moates ostrich but they don't sell it locally from where i live, trying to get one would probably cost very much since tariffs are very high for electronics stuff.

I was also thinking of using dip through hole chips. Almost all of the chips are avaialble in through hole except the ftdi chip. Why was the schematic made with atmega16 and not atmega16u ? which has usb support? to eliminate the need for ftdi chip?
 

Offline free_electron

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Re: looking for a rom/ram emulator
« Reply #33 on: October 07, 2015, 08:36:40 pm »
does that matter ? the target system is irrelevant.

In my case the target is the control board of the combustion engine of a car (automotive purpose).

cause that is your development box

because it's in the project constraints, and because  my customers need something like that, during our "tests" we need to use an embedded linux board, and this board should control the ROM/emulator, the whole should be embedded with it, and able to reprogram it on demand, there is a custom App that generates the rom, and this program needs to access data from the can bus, plus other data from fpga, there are two systems, linux and VxWorks, we have the full control of both, from the source code side.

Elektor magazine made an eprom emulator in the mid 90's that was using a 62256 ram , some counters and hooked up to a standard printerport.
you would take the binary image of the rom and simply 'copy' it to LPT1.

have you read what I have written ? I have already built three ROM emulators for hobby purposes, they are working with linux (see the above example, it's a control shell I have written, it's the simplest) but I do not have the convenience (1) use them for my customers (because of a lot of reasons), I prefer to consider the recycling of an existing product, adapting my software to it, so I am looking for a commercial product with a full documented USB protocol.

(1) I might propose my ROM emulators to the executive manager, I need his help (and his authorization) to build 4 thousand units, but in this case … they also have to pay my design (I am a consultant). These units should be shipped to our final customers in order to make them able to run their and our testes autonomously, providing data back to us, just through an internet socket (a tcp/ip application, which runs inside the linux board, has been already designed for that).

looks like you painted yourself in a bit of a corner...
the truth is that things like eprom emulators are all designed to work with a bit of driver software. and that will invariably be win/tel.

you may have a chance using an emulator that uses an rs232 link. you can always slap a usb->rs232 converter in front of it. those protocols will be open.
Try Emutec. they may have one that works for you
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Offline solac

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Re: looking for a rom/ram emulator
« Reply #34 on: October 12, 2015, 03:43:01 pm »
hi need some help with the constrution of honda rtp. i replace the ft232bl with ft232rl since its whats available locally. i have checked the data sheet and it seems to be the same, and it does not need an external oscilator? Also i bought a ram with the same part number is62c256 problem is its 70ns would it make a lot of difference in terms of speed? im using all dip packages for the ic except for the resistors and passive capacitors.

thanks
 

Offline grantb5

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Re: looking for a rom/ram emulator
« Reply #35 on: November 25, 2018, 12:44:22 am »

have you read what I have written ? I have already built three ROM emulators for hobby purposes, they are working with linux (see the above example, it's a control shell I have written, it's the simplest) but I do not have the convenience (1) use them for my customers (because of a lot of reasons), I prefer to consider the recycling of an existing product, adapting my software to it, so I am looking for a commercial product with a full documented USB protocol.

FWIW there is one called the Momik MemSIM2 that is serial over USB and the protocol is available on Github I think. It's very inexpensive too which is nice.
 

Offline technix

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Re: looking for a rom/ram emulator
« Reply #36 on: November 28, 2018, 05:07:57 am »
"Quote from: free_electron on October 07, 2015, 07:30:11 am"

after 3 years  :-DD
I am now looking into building one myself for a few projects that needs bootstrapping. I need UNIX support so a bit of challenge here.

My general idea here is to build a small module that takes whatever source protocol and turn it into 3.3V SPI Flash. This way I can either just use a W25Q128 in DIP-8 or use a STM32L432 to emulate a SPI Flash.
 


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