This small release fixes an important bug in the GEMDOS drive and enables MIDI as a logging device. GEMDOS drive fix This fix solves a memory management issue with the initial release. It replaces a system call with another one, that was made available in TOS starting from version 1.04. So this fixed version now only works on TOS versions 1.04 and up. Everything is explained in the updated documentation.

Happy new year! It has been quite some time without any zeST release, so let’s celebrate this new year with a new release! On the menu: a brand new GEMDOS drive, real-time clock implementation, improvements around network connectivity and joystick/gamepad management and some driver updates. A new GEMDOS drive The GEMDOS drive is a new way of implementing a hard disk drive on zeST. It maps the contents of a directory on the local Linux system to a logical disk drive on the Atari.

Here comes a new release with performance improvements and useful improvements on the software side. Turbo mode optimisation There has been a pass of optimisations in the memory accesses in Turbo mode. The two wait cycles on reads are gone, and read burst management has had its latency reduced by a few cycles. Performance has therefore improved, as you can see on the new results: The average peformance is now 540% of that of a real ST, which is 28% faster than the previous release of zeST (420%).

This new release adds major improvements, that I describe in this article. Turbo mode zeST now has a turbo mode, allowing the 68000 CPU to run at 50 MHz, instead of the original 8 MHz. Of course the goal of turbo mode is no longer cycle exactness, but rather achieve the maximum possible available performance allowed by your FPGA hardware. Switch turbo mode off, and you’re back to cycle exact 8 MHz again.

Here is the new release of zeST, mostly with fixes to make life better. Scan doubler rework The scan doubler has received particular attention for this new release. Indeed, a large part of its logic has been rewritten. This module is one of the first implemented in zeST, even before I got the TOS system to boot. It was already there when I displayed my first image out of the Atari ST logic on a HDMI screen.

This latest release fixes an important bug that made the system hang in specific memory access conditions. Specifically, on the Z7-Lite board, just changing the floppy disk image and then resetting the system triggered the bug. I didn’t see it because most of the development and debugging was done using my Z-Turn board. This bug was introduced in last September’s release, with the new memory interface that featured an internal cache.

New user interface A complete rework on the user interface has been performed, and this results in a totally new, user-friendly UI. The old MS-DOS-style “text mode buttons” design has been replaced with a list view system, in which you can navigate all the entries and settings using the arrow keys. Joystick support will be added in a future release. Instead of the mono-space Atari system font, the interface is now using a clean, proportional bitmap font.

A new release of zeST is available! On the menu: support for a new board, improved floppy management, and bug fix. New board support zeST now fully supports the TE0726 “ZynqBerry” board from Trenz Electronic. This is a Raspberry Pi 3-shaped board that features the same interfaces as the Pi, including 4 USB ports and an audio output jack connector. Porting zeST to this board was rather challenging because I had to deal with various issues that I never encountered on other boards before:

A new release of zeST is available! The following is a comprehensive description of the changes. More demos working A number of fixes have been made, improving compatibility with some demos that didn’t load into zeST initially. They mainly improve the loading of floppy disk images on some demos that use their own low-level code to address the Atari ST’s floppy disk controller and DMA system. As you can see from the dedicated GitHub issue page, all demos I had previously identified as not able to load are now working.

This new zeST release brings a major fix in memory management, introduces “shifter wakestates” , properly implements MMU configuration, and includes other small fixes. Memory management zeST now includes a much better manager for accessing the main DDR memory of the Zynq board it’s running on. This is not strictly related to the Atari ST implementation, but rater to the management of the host hardware to be able to use it with the best performance.