ra1fh / memsimctl

Command line tool to control the memsim2 EPROM simulator

memsimctl

Command line tool to control memSIM2 EPROM simulator.

Building

$ make
$ make install

Platform Support

memsimctl has been successfully tested on:

• Fedora 33 (x86_64)
• Ubuntu 20.04 (x86_64)
• OpenBSD 6.8/6.9 (x86_64, sparc64)
• FreeBSD 12.1 (x86_64)
• Raspbian 10 (armv7)

Usage

usage: memsimctl [-d device] [-s start] [-r reset] [-z memfill] -m memtype -w file
       memsimctl [-d device] -m memtype -D
       memsimctl [-d device] -m memtype -E
       memsimctl [-d device] -i
       memsimctl -h
       memsimctl -L

  -d device     serial device
  -D            disable buffers
  -E            enable buffers
  -h            print help
  -i            identify device
  -L            list memory types
  -m memtype    select memory type
  -s start      start address where input file is loaded
  -r reset      reset in ms, < 0 negative, > 0 positve, = 0 off
  -v            verbose output
  -w file       write file to emulator
  -z memfill    fill value for unused memory

The following example demonstrates a few command line options to send a 4K image.bin to the simulator in 2764 mode with a 100ms negative reset pulse:

$ memsimctl -m 2764 -r -100 -s 0x1000 -z 0xff -w image.bin

[0x01000 : 0x01fff] (0x01000) image.bin
[0x00000 : 0x01fff] (0x02000) EPROM 2764 0xff -100ms

Transfer:   OK

The input file (-w) has to be in raw binary format. The specified start address (-s) determines where the input is mapped into the simulator memory. The remaining memory will be filled with 0x00 or the specified fill value (-z).

Enabling the output buffers is done implicitly when a new memory image has been transmitted. The -D option can be used to disable output buffers.

The -L option lists available memory types and sizes.

The -i option sends an identify command to the device. The response indicates the version and memory size of the device:

$ memsimctl -i
Device:  /dev/ttyUSB0
Version: 1
Memory:  1

Protocol Details

The following information has be gathered by observing the USB communication. The description is likely incomplete.

MI

The MI command can be used to identify the device and the version of the device:

MI000000000000\r\n

The device responds with:

MI110000000000\r\n

The two digits seem to indicate version '1' and memory size '1' (512KB).

MC

The MC command is the configuration command that sets up various parameters of the memSIM2 device. The buffer control is effective immediately. The reset pulse is only issued after data transmission.

MC0P123EN000FF\r\n
  ||^^^||
  || | |+----- presumably selftest (N=disable, unknown how to enable)
  || | +------ buffer control (D=disable, E=enable)
  || +-------- reset pulse time 123ms (255ms max)
  |+---------- reset polarity (P=positive, N=negative, 0=off)
  +----------- EPROM model selection

The response repeats the request string with 'X' for the self-test:

MC0P123EX000FF\r\n

The following EPROM models are defined:

Model	Protocol Value	Size
2764	0	8 KB
27128	1	16 KB
27256	2	32 KB
27512	3	64 KB
27010	4	128 KB
27020	5	256 KB
27040	6	512 KB

MD

The MD command starts the data transmission to the memSIM2 device.

MD0512000000FF\r\n
   ^^^
    |
    +---------- data in KB

Following the header, the data is being transmitted in binary. The device acknowledges successful transmission with:

MD0512000000FF\r\n

After data transmission, the buffers are enabled immediately, indicated by the "READY" LED. The reset pulse will be triggered as well as configured with the previous reset command.