Q68

The Q68 is a complete replacement system for the QL. It is designed by Peter Graf, who also designed the Q40 and Q60 systems, and became available in limited quantities in December 2017.

The Q68, unlike its predecessors, is based around a single FPGA chip which implements a 68000 compatible processor and internal QL peripherals. The Q68 interacts with the user through a standard PC keyboard, mouse and SVGA monitor, while mass storage is provided by up to two SDHC cards. It is available in a black aluminium custom case or as a mainboard only.

• 68000 compatible processor, 40 MHz clock, 32-bit address bus
• 32 MB SDRAM, of which 28MB is available to the operating system
• 96 KB ROM area, used by internal boot loader and usable as ROM emulation area for loadable operating system
• Two SDHC card slots
• One PS/2 connector for connecting keyboard and mouse (via splitter cable)
• VGA connector for connecting a standard PC monitor
• Line/headphone output for Stereo Sampled Sound System
• Real-time clock
• Serial port via DB9 connector, speed up to 460k baud
• I²C interface
• 10base-T Ethernet interface
• Extension bus

The Q68 supports eight video modes:

• 256x256, 8 colours (QL compatible)
• 512x256, 4 colours (QL compatible)
• 512x256, 65536 colours (Q40/Q60 high colour)
• 1024x512, 65536 colours (Q40/Q60 high colour)
• 1024x768, 4 colours
• 1024x768, 256 colours (Aurora mode)
• 512x384, 65536 colours
• 1024x768, 65536 colours

As the video RAM is shared with the main RAM, using the higher resolutions with 256 or 65536 colour modes may slow down processing considerably (up to 56 percent in 1024x768x65536 mode). However, there is a 12K section of 'fast memory' available between addresses $19000 and $1BFFF which does not suffer from this contention and can be used to accommodate timing-critical code.

The Q68 is supplied with the SMSQ/E operating system which is loaded from the SDHC card by the internal boot loader. This particular version of SMSQ/E also contains the necessary drivers for the Q68 hardware. Since the Q68 allows any ROM image to be loaded into the 96K ROM-emulation memory area, it is also possible to run Minerva or even legacy Sinclair ROMs on the Q68, using suitable extension ROM images containing the hardware drivers. A Q68 port of Minerva has been available on GitHub since July 2018.

Access to mass storage is provided using QXL.WIN-style container files which have to be placed onto a FAT32-formatted partition on the SDHC cards. The Q68 has some restrictions on this in that the container files must lie in contiguous sectors on the card, and within the first 16 directory entries. QUBIDE-style container files can also be accessed using the QUBx_ device.

In order to exchange files with other systems, a second partition may be formatted on the card using the FAT16 file system, which is accessible by SMSQ/E using the FATx_ device.

In June 2019, driver software became available which allows the Q68 to be connected to the original QL's QLAN ports, using a few additional electronic components. This allows the Q68 to be used as a file server for the QL, providing gigabytes of mass storage.

In December 2020, driver software for the ethernet interface also became available which supports the ARP, ICMP and UDP protocols. It also supports the IP Network driver to re-enable some standard QL networking facilities over TCP/IP.