Minesweeper is written by zxteammember bodo in pure basic. Can i sell a proprietary software with an lgpl library bundled along with it, without making. The unexpanded zx81s tiny memory presents a major challenge to programmers. This was not just to save money but is also related to the way. System variables of the sinclair zx81 memory map of the ram reserved by the system.
The minstrel zx80 clone uses a larger eprom, a 27c64 up to a 27c512, with multiple 8k chunks selectable via jumpers so you can have a choice of rom versions. This is a zx81 compatible z80 based 8 bit computer kit with 32k ram. Contribute to domahonyzx81 development by creating an account on github. It is ok by me to extract the individual articles and other material and. Basic programs and file formats bumbershoot software. Only minor changes have been made to the original source code. But on an unexpanded zx81, the 1k video memory bank is the only ram. Tynemouth software launches minstrel issue 3 sinclair zx81 compatible microcomputer kit with 32kb of builtin ram, the board can be used standalone or as a dropin replacement in failed sinclair zx81s and timex sinclair s. Adding nmi fastslow mode makes it zx81 compatible, so it can run most zx81 ts or zx80 software. Sync magazine was a relatively shortlived glossy magazine dedicated to the timex sinclair zx80 zx81 models of computers. With basic you will have modified and new zx81basic commands. Nonetheless, ingenious programmers are able to achieve a surprising amount with just 1 kb. Minesweeper recoded by one of the zxteam members bodo to be compilable in mcoder2.
So here goes my first installment of the zx81 modernization project. Software as described above, zx80 and zx81 cassette files are completely incompatible to each other. Sinclair zx81 webring webring with a main goal of supporting the zx81 community with information about activities for the computer and its clones. However, the zx81 basic syntax is mostly compatible to zx80 syntax, so that zx80 software could be easily imported to zx81 with little changes. An exciting additional feature of the chroma 81 interface is its ability to add colour to the zx81 display. Minesweeper for your zx81 will also run under zx81emulator xtender. I also wrote the listing script, which uses the character set data directly from the zx81 rom to produce an authentic zx81 look.
This was not just to save money but is also related to the way that the video display is generated. The zx97lite is a simplified zx97 designed to fit on one single sided pcb. Tynemouth software llp old computers, new computers, bespoke web design and software development, computer repairs, it and media services uk tuesday, 22 july 2014 zx81 internal 16k ram. According to the system variables of the sinclair zx81, memory location 16398 and 16399 form a 16bit value containing the current address of print position in display file.
Sinclair lot of 8 zx81 computers memory modules power supplies manuals shrwrap. The zx81 was a lowerchipcount successor to the zx80 a machine i would dearly love to add to my collection. The vla81 is a modern plugin replacement for the zx81 ula. I was wondering if anybody knows where i can get a detailed memory map for the zx81.
Resources for the sinclair zx80 and zx81 home computers. The microzx81 is a zx81 project in smd with a double sided pcb. All programs in this app store are sampled from cassettes. A choice of screen colour, and a screen invert option. Download software for zx81 and emulator here i will present some nice software for your zx81 which is written by zxteam members and cannot be found in other sites. There are two ways to run machine code on the spectrum. Screenshots were taken using the eightyone emulator. Base plate i can supply a clear perspex base plate as shown in the pictures to mount the minstrel and keyboard, or. Note that the m1not mod is not needed with the 32k internal memory. It was a fun oneday project to build, all of the components were. Tzx files through the computer sound card so that you can load them on to a real zx81. Tynemouth software launches minstrel issue 3 sinclair zx81. In place of a dedicated monitor, the zx81 was designed to output video to standard television set.
The ram has been upgraded to 32k and supports most high resolution graphics mechanisms used on the zx81. Its mainly about the zx spectrum, but quite a lot of zx80, zx81 and ql stuff appears in it. And on an expanded one, as i understand it, the onboard ram is disabled in favor of only using the expansion ram. Lowcosttuning expand your memory up to 32k a selfmade project in three steps you need the schematic of zx81, some knowhow in soldering and some parts you can buy for pocketmoney. Packing a heady 1kb of ram, you would have needed many, many. Download software for zx81 and emulator sinclair zx81 zx80. The zx81 display file can be moved to any part of memory without a crash, machine code can also be executed in the top 32k of memory. Use of this attributes file requires dedicated software to control it. Im hunting around for an equivalent of the zx81s ramtop to do that automatically but cant find anything yet. Minstrel issue 3 zx81 compatible computer kit from.
The 64k ram pack only gave you 56k as you still need to have the rom in the z80s memory map. The sinclair zx81 was small, black with only 1k of memory, but 30 years ago it helped to spark a generation of programming wizards. The sinclair zx80 was one of the first real home computers it was supplied in kit form to home electronics enthusiasts for just. All equipment and all building projects worked and still works.
L break into program zx spectrum screen memory layout. Internal 32k memory support high or low for the different hires schemes. Basic programs and file formats 1 reply our ultimate goal with the zx81 here is to work out how to get our own machine code into it so we can watch it go, and maybe also learn about the oddities of the platform. One mode provides an attributes file similar in concept to that found on the spectrum. Existing m1not enabled internal memory will work fine with the default zx81 memory mapping selected. The same slot bus was continued on the zx81, and later the zx spectrum, which encouraged a small cottage industry of expansion devices, including memory packs, printers and even floppy drives. Timex sinclair 2068 memory map and rom disassembly. You can reserve memory for your code and preserve all the system memory areas. The ram bas been expanded to 32k positioned from 8k40k in the memory map, mirrored in the top 16k for the display file with support for various high resolution graphics modes. The unexpanded zx81 s tiny memory presents a major challenge to programmers. It is ok by me to extract the individual articles and other material and distribute them separately. Were there any gamessoftware that used memory beyond what was advertised available to basic on the machine. Zx80zx81 memory map and system area zx80zx81 memory mirrors and expansions zx80zx81 memory binary datamachine code programs zx80zx81. The zxpand interface offers 32k of expanded memory which is configurable to support various hiresolution graphics modes, instant file access to.
The original sinclair zx80 ram pack held either 1, 2 or 3 kb of static ram and a later model held 16 kb of dynamic ram dram. This app focuses on the sinclair zx81 experience and is loaded with example software. Here is my tried and proven idea for full decoding of a 32k sram chip in the zx81 memory map. Our ultimate goal with the zx81 here is to work out how to get our own machine code into it so we can watch it go, and maybe also learn about the oddities of the platform. Sinclair zx81 basic programming by steven vickers second edition 1981 copyright 1980 sinclair research limited reproduced with permission from the publisher. Memory map as designed, where current peripherals fit in the map and suggestions about standardization.
The zx80 could be upgraded to zx81 style basic, which came in an 8k rom. I wrote the fileserver myself, as well as the client software needed on the zx81 to do the communication with the ql. Minesweeper for your zx81 will also run under zx81 emulator xtender. Please note that the system is completely self contained and this means you cannot remotely add code, more games etc. Thousands of zx81 programs were published, either as. Im hunting around for an equivalent of the zx81 s ramtop to do that automatically but cant find anything yet. The sinclair zx81 was released 1981 in the uk and later in 1982 in a slightly modified form as the timex sinclair in the united states. Unlike its successor the zx spectrum, the zx81 was not particularly belovedive only seen a few instances of highquality. The availability of emulators do help with development, as will the zx81 mmc memory card interface. Inverse or normal video and choice of black or white.
Some of the software requires the hiresolution graphics drivers developed in software and a graphics capable ram pack by matthias swatosch details are available from matthias swatosch site. Home periodicals sq syntax quarterly zx memory map zx memory map memory map as designed, where current peripherals fit in the map and suggestions about standardization. Requires the zx81 membrane connectors from the connectors option. As i understand it, the zx81 video system, which resides in the ula like all the rest of the machinespecific logic, works by using the cpu as an address generator. User selectable memory mapping allows the zx97l to boot directly from user mc code in ram. Keyboards and keyboard accessories for the zx81 and ts. Sinclair zx world about the sinclair zx80 and zx81 home. Oct, 2019 the zx80 could be upgraded to zx81 style basic, which came in an 8k rom. This version has been adapted to work with a redefined characters available through hiresolution display interfaces which are mapped to 3000h in ram. Sinclair vintage computers and mainframes for sale ebay. The sinclair zx81 zxpand interface will also allow you to connect an atari style 9 pin joystick port to play either specially written or specially adapted. Data could now be exchanged at a rate of 9600 baud seconds for 16k and could be accessed in a sufficiently quick and simple way. Assembly listing of the operating system of the sinclair zx81. Get the best deals on sinclair vintage computers and mainframes when you shop the largest online selection at.
Designed as a lowcost introduction to home computing, the zx81 was designed to be small, simple, and cheap. As secondary memory the zx81 doesnt use hard drives, floppy disks or flash memory, but a cassette player. The zx97l is a complete zx81 using discrete logic chips with 32k of battery backup ram and 32k of eprom. Mar 11, 2011 the sinclair zx81 was small, black with only 1k of memory, but 30 years ago it helped to spark a generation of programming wizards. Begin address end address description 0000h 1fffh original zx81 8k rom area. The original compiler for sinclair basic on the zx81, written by david c. Memory map the following table shows the memory map for four machines.
The zx80kdlx version uses sil sockets mounted under the board to allow you to attach a zx80kdlx or zx81kdlx none included. Ive not tested if the programs in basfiles can be converted back to pfiles. Zx80 basic checking free memory retrocomputing stack. Z81 a zx81 emulator for vga pcs running linux xz81 a zx81 emulator for x z81txt a textmode zx81 emulator for the linux console. The zx81 has the same microprocessor and runs at the same speed as the zx80, but it has a better basic programming language and is cheaper to produce, due to having fewer chips and a simpler design. Tynemouth software launches minstrel issue 3 sinclair zx81compatible microcomputer kit with 32kb of builtin ram, the board can be used standalone or as a dropin replacement in failed sinclair zx81s and timex sinclair s. The minstrel issue 3 adds the slow mode to allow zx81 compatibility. Minstrel zx80 clone from tynemouth software on tindie. The spectrum screen memory map is split into two sections. The original 1k was displaced when a ram pack was added. Two colour modes are provided, each supporting up to 15 colours.
Software exchange i improved the 3dlabyrinth software. Stevens zx81 computer links and information from an enthusiast. As you know the zx81 uses an incomplete decoding scheme for ramcs and romcs. Simply displaying a full screen takes up to 793 bytes, the system variables take up another 125 bytes, and the program, input buffer and stacks need more memory on top of that. Actually, ive been looking at the zx81s memory map, and it appears that. Mapping extra 128k video ram into conventionalems memory. Threlfall, and published by pss personal software services in 1983. The ram pack was topheavy and was supported only by. Nowadays you can develop software for the zx81 also in c with the compiler z88dk, but it requires a another computer. Ram packs and memory expansion for the zx81 and ts. Weve given you as much direct memory as the zx81 can take, and youre now in a. Having been one of the few in canada to have a zx80, i have a fond memory of the computer. The memory map on a 48k spectrum is fairly straightforward.