Créé par Avery Lee (l’auteur de VirtualDub), il s’agit d’un émulateur d’Atari 8 bits (800/800XL/130XE) disponible en 32 et 64 bits. Il dispose de beaucoup d’options ainsi que d’une bonne compatibilité. Il prend en charge les jeux protégés conformément à l’émulation. Il s’agit d’une version de développement au stade de béta.
– Fixes reboot issue with Happy 1050. The problem was that the controller CPU was getting reset before the ROM banking logic, so sometimes it was trying to boot from one bank with the reset vector of the other.
– Rename Tiger 1050 -> Tygrys 1050. The firmware tag and device name have changed, so you will have to re-set those up.
– Reimplemented SIO transmissions from full drive to POKEY. This eliminates a byte delay that was causing Happy warp mode to fail, since it has a very fast speed switch between ACK and Complete.
– Drive emulation speed is now adjusted for NTSC/PAL. This is unfortunately the result of investigating high-speed write issues with the Speedy 1050, which turned out to be due to a marginal read loop on the drive side. Speedy 1050 high speed mode operates at a POKEY divisor of 9, or 32 computer cycles per bit. Reads are fine, but data frame writes are tight on the drive because the read loop is 180 cycles at 1MHz. In PAL, this just barely works because 320 cycles @ 1.77MHz comes out to 180.8 drive cycles, but in NTSC 320 cycles @ 1.79MHz = 178.7 drive cycles. This was causing the drive to lose a bit halfway through the data frame in NTSC. 🙁
– Disk change is now emulated, including the write protect sensor and the not ready bit on the 1050. This is necessary for the 1050 to recheck density and for enhanced drives to flush their track read buffer. As a result, you will now hear the motor spin up and possibly a seek when switching disks. The not ready status bit is also now continuously updated after type II/III commands, as this is required by the 1050 (and yet another omission in the FDC docs).
– Fixed FDC transfer timing being too fast for single density in 1050 drives.
– Read/write operations now fail on half tracks.
– Formatting is now supported for MFM formats (enhanced/double density).
– Tweaked the FDC to work around some firmwares locking up when trying to format a disk with formatting blocked (VRWSafe mode) because they cannot handle a write protect error on the Write Track command. 810 and 1050 now fail the format command quickly; some enhanced drive firmwares will still attempt the format, and for protected disks on those drives you will need to force the disk mode to full read-only (R/O).
– Fixed transmission errors with full drive emulation when SIO burst mode is enabled for disk drives; this is now ignored by the full drive emulator since it is not supported.
– Fixed a bug with the standard drive emulator not getting re-enabled when removing a full disk drive.
– The swap/rotate commands now work for full disk drives.
– Added .fdc and .riot commands in the debugger.
