Sharp MZ

Teaser for SDLEP-READER working with MZ-700.

Ohoh that magical "LOADING xxx" message! At last, a program is running on my MZ-700!

Nice Is this a read-only solution, or is it possible to write to "tape" as well?

This is a read-only solution. As the author says, tape solutions are nightmares to use and too slow so he doesn't see any useful purpose to implement it.

The reason is probably due to some limitations:

1) File "name" is selected by a 7-bit DIP. So you have up to 128 files.
2) FAT is only used for searching a particular file with a 7-bit pattern (from 0000000.lep to 1111111.lep), that is, looking for the first sector of the file data. Once the first sector is retrieved, the remaining sectors of the file data are read contiguously.
3) Pin RX0 is used for MOTOR signal, so there is no room for adding WRITE signal - at least, with the proposed schematics.

Point 1 makes uneasy to select a file data to write.
Point 2 makes very hard to write a file data in contiguous sectors.

All points need more changes in the firmware.

In my case, the writing process is not very meaningful for a tape-like device.

It works but it has an annoying behavior. I may need to invert the MOTOR signal. Now, I'm forced to connect MOTOR and SENSE signals to GND respectively to allow SDLEP-READER to transmit file data and bypass the blocking "[PRESS] PLAY" message.

So it means I need to push the RESET button on the Arduino to start the transmission again after typing "L" at the MONITOR prompt.

I'm waiting for an ordered tool to reprogram the Arduino firmware.

When I receive this tool, I plan to invert the MOTOR signal in the firmware to check whether I can let MZ-700 activate the file data transmission.

Maybe we could add more features as a way to display and select files. Maybe we could use MZF instead of LEP. And I also hope to be able to make the turboloader as well. Maybe to be able to read sectors in a non-contiguous way. And so on.

Yes, it needs a more userfriendly user interface, but that is pretty easy to do with the Arduino. There are many displays and libraries that are really easy to use.

Ok, the original turbo loader had a hardcoded value for DLY3 to $15 which is for 3600 baud. I think SDLEP-READER may have a hard job to cope with 3600 baud (firmware delay granularity is 50 µS). By setting $1F instead (2400 baud), I was able to read SEND-1 at 2X speed. However, I have found this article which explains the tape timings must be different according to where the monitor code resides. If running MONITOR from RAM, you need $27 or $28 instead of $1f. Maybe that X3 is still reachable with the right timings ($1b instead of $15)...