The Spectrum SE Andrew Owen speaks for Subliminal Extacy about one of the most ambitious projects to hit the Speccy - What is the Spectrum SE? I am aiming to build a modern Z80 based computer. I expect it to be used for everything modern x86 and PPC computers are used for because it will be powerful enough to do it but cheap enough for people in even the poorest parts of the world to be able to afford. - Why have you chosen to base it on the Spectrum? I got my first Spectrum in 1984. It was a Spectrum +. The manual was crap so I taught myself BASIC by refering to the commands on the keyboard (at last a reason for that layout). When I moved on to an Atari ST I found it much harder to create my own programs and I missed that about the Spectrum. When I got Gunter Woigk's Mac Spectacle in about 1995 (the early version with no sound support, let alone 128K) I started writing my own software again. So, to answer your question, it is impossible for the average user to sit down and write a program in one go for modern operating systems. They are simply too complicated. I thought, given the number of articles posted on CSS, there was a real demand for a new Spectrum for precisely this reason. - What are the major features? Well, you have to think of it as a new computer that just happens to be able to run Spectrum software really, a bit like the Peters Sprinter only better. The CPU is a Z84C00 at 21.2814 Mhz. This can be stepped down to 3.5469 Mhz for the purposes of 100% accurate 128 mode execution (although there isn't actually a 128 mode). It will be possible to change the processor speed from software or via a turbo button. The software switch will be compatible with the Scorpion if possible. The finished machine will be able to access between 1бМВ and 32MB (not yet determined). The paging system still has to be sorted out because of trying to maintain compatibility with expanded Pentagons and Scorpions. Port 7FFD will behave exactly like a 128 (with D6 and D7 reserved for future expansion). The first four bits of port 1FFD (D0-D3) will act like the +3 (in order to support PLUSЗDOS software). The remainder will be as compatible with the expanded Scorpion and Pentagon as possible. The ULA will be replaced with a microcontroller in order to display the screens at full speed. Standard Spectrum and TS2068 modes will be supported with the addition of palettes. The FLASH/BRIGHT bits of the attribute map will be used to specify a CLUT of 8 colours for a maximum of 32 colours on screen in the standard Spectrum mode without palette switching. There will be two YM2203s in place of the AY chip. They are register compatible so existing AY stuff will work but they are more powerful and using two together full digital sound should be possible. I haven't decided what to do about covox support since I can't get any decent info on it but if I do I may end up emulating it via the two YM2203s. There will also be a GM-MIDI chip and a DAC. The output will be a 16-bit stereo signal at ЧЧKhz. The keyboard and mouse may be PS/2, PSX or USB depending on what works out cheapest. There will be at least one serial port capable of using a 56K modem (for internet connection). There will also be a parallel port. Both these will be driven via dedicated hardware. There may also be support for Playstation game controllers and memory cards (128K capacity). The first four ROMs are mapped in using the +3 paging system. There may be a fifth ROM is paged in externally using the ROM-CS line in order to support TR-DOS. ROM 0 contains the BIOS. This performs any system tests and intialises the machine before passing control on to ROM 1 (BASIC). The advantage of this is that the RST 0 instruction can now be used from ROM 1 to provide up to 65536 system commands. ROM 1 contains a version of BASIC derived from the original 48K machine. However, BASIC extensions are stored in ROM 0 and called on the fly from ROM 1. ROM 2 contains the primary disk system of the SE; PLUSЗDOS. This provides support for the majority of +3 applications and allows +3, CP/M, and CPC disks to be read. The ROM also contains IDEDOS which allows the use of a hard disk. ROM 3 is empty at the moment but will probably end up containing a monitor/assembler/disassembler and snapshot tool while ROM 4 will eventually contain a version of TR-DOS patched to use the +3's disk interface. ROM 0 and ROM 1 can be used independently of the other ROMs on modified 128 and +2 systems. The machine will also include full international character support (including from BASIC), 42 column text from BASIC in 256x192 mode, 85 column text from BASIC in 512x192 mode, support for CP/M 3.0, and a user sizeable RAM disk (accessible from BASIC using 128 or +3 commands). - To what extent is it compatible with existing Spectrums and clones? Compatiblity is very important for the machine to be a success. It will be PORT compatible with the original Spectrum but it will also support the enhanced video modes of the TS2068 (which are also used by some Pentagons), PLUSЗDOS, IDEDOS, TR-DOS (as used on the Scorpion and Pentagon), the extended memory maps of the Scorpion and Pentagon. The BASIC will support the commands of the Spectrum, TK90X, Spectrum 128 and TS2068 in one mode. Programs written for any of these machines can be loaded in and RUN without modification in the standard mode. The BASIC will also support the extensions of BASIC 64, which means that the graphics commands will work in 512x192 mode. - How much has been completed so far? Most of the work so far has been spent on debugging the original Spectrum BASIC and the 128 editor ROM. I've made some interesting discoveries along the way, for instance, there's a whole chunk of useless code in the 128 BASIC ROM (and hence in the Pentagon, Scorpion, +2, +3 and +2A). In fact the original BASIC ROM can be used with the +3/+2A without modification to improve compatibility. On the 128 and +2 three bytes in ROM 0 have to be changed. It's amazing really. Anyway, back to the question. The BASIC has been completely debugged. It is certified 100% bug free. It has also been tested extensively with a wide range of software for compatibility and no problems have been found so far. The ROM layout of the machine has been determined. The BIOS and BASIC extensions live in ROM 0 (I'll also put the GUI toolbox in there if there's enough room). BASIC lives in ROM 1 (even on the +3 test version). PLUSЗDOS and IDEDOS (an extension to allow the use of hard disks by Garry Lancaster) is in ROM 2. ROM 3 is undecided. And I haven't decided how to implement TR-DOS support yet. I could do it by emulation or by direct support (although I will probably go for emulation for copyright reasons, this will still allow TR-DOS software from the former USSR to run without problems). --- For more information about the SE, visit http://www.brandnewco.org/se/. You can also contact Andrew at aowen@brandnewco.org to subscribe to the 'SE-mail' newsletter.