FPGA Resources - Running TUTOR Monitor

A project log for Retro 68000 CPU in an FPGA

Making a Retrocomputer with a 68000 CPU in an FPGA 07/10/2020 at 13:420 Comments

I wanted to run Jeff Trantor's build of the TUTOR monitor since it has a lot more features than the TS2BUG. The User Manual for the MEX68KECB details the commands for TUTOR.

It requires more ROM resources than the TS2BUG monitor design used. The TS2BUG monitor uses less than 4 KB of memory. The TUTOR monitor requires 16KB. 

The FPGA has 56 of 1 KB blocks so there is enough RAM space to have 32KB of SRAM and  16KB of ROM and still have a full-featured VDU (color attributes per character and 256 characters).

The resource use (with the 4 KB TS2BUG) is:

That breaks down to:

The ROM megawizard values are:

To make the change in the MegaWizard requires setting the memory size to 8K of 16-bits and changing the MIF file to the TUTOR monitor. That leaves a single 1K block of SRAM in the FPGA.

I also had several changes to the ROM address decoder to use less address bits. This will still be backwards compatible with the TS2MON.

Both the TS2TBUG and TUTOR run without re-compiling of Jeff Tranter's builds. All that is needed is converting the S record or HEX file to an Altera MIF file (process described in previous BLOG).

TUTOR 1.3 now works!!!

Loaded to GitHub here.