diff --git a/README.md b/README.md new file mode 100644 index 0000000..65fc066 --- /dev/null +++ b/README.md @@ -0,0 +1,31 @@ +## David's ST Booster (DSTB) + +#### A low-cost DIY 16MHz 68000 accelerator with 8MB fast AltRAM and optional ROM cacheing + +Fitting into a small footprint, just 3mm wider than the 68000 socket into which this plugs, the board (\~$4) contains one XC95144XL-100 CPLD (\~$5), one 32Mbit TSSOP-II-54 SDRAM chip (~$5), two level-shifting buffers (\~$6), one 5 or 3.3V 66MHz oscillator in a 7x5mm package (\~$4) and a 3.3V LDO voltage regulator (\~$2) as the core components. + +This provides all the interface between the ST and a 16MHz capable 68000. The 68000 will run at the oscillator frequency divided by four, so 16.5MHz in normal configuration. + +The AltRAM runs at at full speed for a 16MHz processor, offering throughput of around 7.7MB/s compared to ST-RAM's 3.7MB/s. + +Firmware source (ISE), board design files (KiCAD) and any source for support programs will be published at each release. + +#### Cost & requirements + +I anticipate a single board can be hand assembled for approximately 30USD. You may need to acquire a 16MHz capable DIP-64 68000 to pair with it if your old 8MHz chip cannot handle the faster clock. + +#### Manual + +At the moment, there is no manual. This will be written in due course. + +There is a build video available at https://youtu.be/VHx3kat0Q6M + +#### Software + +See https://github.com/dh219/DSTB-tools for the 'AltRAM' or 'AltROM' programs (NB. this board is not compatible with 'ExxosRAM.PRG'). + +EmuTOS automatically recognises and activate AltRAM. + +--- + +*Copyright 2022 D Henderson, released under GPL2.0*