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Multiface 3 programming guide anywhere?I'm interested in the tantalising little bit of text at the bottom of my Multiface 3 manual (under the "Using 8K RAM" section): "Please send a SAE…
... :
IN 0x1f3f, returns the last written value to 0x1ffd port ...
IN 0x7f3f, returns the last written value to 0x7ffd port ... , and to work out which bits of the RAM I could safely use ... locks could then be used to make the DOS code MT-Safe ... -
Rocky Gush Floppy Drive InterfaceI have a Rocky Gush Floppy Drive Interface which I would like to post the details under the Hardware section of the website. What is correct procedur…
... 's actually in the SYM_CODES list, but is used by various RG ... routines to return from a call to the ... 't figured out the D2 $0022 trap. It's the last byte of CALL $0074 ... !
Emulation-wise, I've got the ... -
Joystick Interfaces on +2AJust found out that my DK'Tronics joystick interface doesn't want to play with my +2A (black). The Kempston port works OK, but not the Sinclair port…
... don't think the way the upper byte is used matters much. ... ten if you count the inbuilt Sinclair ports) really ... set a few more bits of the Joystick IDs on that ... , ignore the decoding and just return the state of Joystick # ... 'd be the most common way of getting four ... -
Joystick Interfaces on +2AJust found out that my DK'Tronics joystick interface doesn't want to play with my +2A (black). The Kempston port works OK, but not the Sinclair port…
... I don't think the way the upper byte is used matters much. It ... to set a few more bits of the Joystick IDs on that board ... to say, ignore the decoding and just return the state of Joystick #1 ... feel that'd be the most common way of getting four sticks ... -
Z80 internal compressionThis isn't exactly a ZX Spectrum problem, but since WOS probably has some of the best Z80 coders in the world, I thought I might ask anyway. For my …
... never occurs in the data.
- The last byte of the data block is always ... lot more frequent than byte repetitions, it may ... of another bit for every "copy next byte to output") and fewer bits ... to indicate "repeat a sequence of ... -
Trailblazer - mapped?Anyone mapped Trailblazer yet? I'd kind of like to get hold of the maps. D.
... s a summary of the steps involved in making the maps.
... /> + start of dump loop, ($6590) is first byte of Zone A bytemap ... of dump loop, call DUMPS routine, pattern IDs >=$AE not used ... mark the top of the last full page printed,
. as the last page ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... search/sync, the address of the timing
;; constant used to initialize . ... it to one of the constants
;; used for detecting sync ... one-byte instruction
and 7 ; keep only the lowest three bits of ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... register, but 47loader hasn't used either H or L for ... [/b] wondered about using the parity of the byte read from port 0xFE to ... that keypresses don't affect the bits read, which would mean committing ... can't rely on the parity of the read byte.
With ... -
Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... of crunched data: 15885 bytes.
Literal sequences are used and the safety ... , the last byte of the packed file must be at least 2 bytes above the last byte of the unpacked ... at 0x8000-0xffff. I've used Exomiser 2 in backwards mode ... -
A few questions about ZX Spectrum assemblyHi, I have a few questions about ZX Spectrum assembly language programming: - What's the best assembly tool for ZX Spectrum? I tried a bit the ZXSpi…
... postcount=37"]pissed[/URL] last time I wrote this ... was actually warning you of the nasty things that could ... 0.666, as several bits of the assembler were part-way ... never completed, and the assembler is therefore extremely ... in 0.7 which, used in a certain manner ... -
Issue 3 board with strange piggy-back boardIn case you are interested. I?ve never seen something like this before. I have an Issue 3 board here. When I opened the case and found a strange pig…
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So, basically, the last bit of the IO address bus (which is ... /> The designers have used a huge NAND to isolate the 7 lower bits of the address ... bus, the ... -
SE Basic IV Buffy v4.1 source (WIP)I've been doing a major refactor on the SE Basic source and I'd appreciate a code review from anyone who has time to look at it. I've almost certainl…
... A holds half the form, used four times
bits to
rrca ; the right
the location of the first byte of char data ... -
Help with File Compressor by Mladen PopovicHi, I'm trying to compress BombJack (MCM) and transfer it to a +3 disk (Yes I own the original game :) ). I'm unsure about the addresses to enter in…
... from ZX Blockeditor. I used the Encore release. And ...
Because the code block expands to the last byte 65535. Make sure ... the plus3. Lots of 48k games use 23296 which is used by the ... 1 byte less than the location of the game code. Assemble the depack ... -
Help with File Compressor by Mladen PopovicHi, I'm trying to compress BombJack (MCM) and transfer it to a +3 disk (Yes I own the original game :) ). I'm unsure about the addresses to enter in…
... from ZX Blockeditor. I used the Encore release. And ...
Because the code block expands to the last byte 65535. Make sure ... the plus3. Lots of 48k games use 23296 which is used by the ... 1 byte less than the location of the game code. Assemble the depack ... -
Optimal shifting for set pixel?Hi, I'm optimizing my set pixel code. For speed. But without using partitioned memory (i.e. a table on 256 byte boundary) I have optimal memory addr…
Surely if you're using the last 3 bits of the X-value to set the bit in a byte then aren't you counting them in reverse order to how they appear on the screen? -
Beautiful codeSome people see beauty or something sublime in maths formulas and equations, can anyone suggest examples of beautiful or sublime programming?
... it can be used.
I added the last bit because I ... really dislike self-modifying code. Most of the ... 256-byte boundaries).
Also mentioned here is the overlap of instructions ... -
Clashbasher a new interface to reduce colour clashI've been working on this for a while now. [IMG]http://markamy.uwclub.net/cauldron.JPG[/IMG] Basicly its an add on for a 48k spectrum, which reinte…
... byte parameters which must reside in the parent object: │
│ │
│ VAR byte ... upon the terminal settings of the last frame ... be used to 'park' the ... -
RFC: 64 column font codeIn BASIC, type CLEAR 49999 then import the code at 50000. Then type RANDOMIZE USR 50000. This will create a new channel and attach stream #4 to it. A…
... /> ; The column value is a 6 bits value (0 ... used to update hl below
ld a,(BACKGRND) ; first font byte ... and 11110000b ; mask half of the font byte
xor (hl) ... and 11110000b ; mask half of the font byte
xor (hl) ... -
Understanding the Kempston joystick circuitHere is the schematics: http://www.retroisle.com/sinclair/zxspectrum/Technical/Hardware/KempstonJoystickInterface-Schematics.php Ok, the 74LS138N …
... influenced by the last value transferred on the data bus (the IN I ... combination of slight leakage from the chips connected to the data ... to sum up, the bits in the read byte from the joystick interface would ... level on pin 15 of the 74LS138 decoder. This results ... -
Were there other graphic modes for the ZX Spectrum?I've read that there was a "hi-color" mode that allowed the color clash to be 8x1 instead of 8x8. Maybe I have the name of that mode wrong. I'm…
... s job to generate the address of the next byte to be sent to ... colour machine. The very low cost system used in the ZX81 was ... not suitable. But the new ... in the ULA for the video system other than the three bits for the border ... -
Question of contentionI'm not desperate to go digging through technical descriptions in depth, but one thing bugs me about the Speccy's video contention model - and that's…
... are talking about 16k byte DRAM chips) of the address to be presented ... once the first data byte has been read, the ULA changes the last 7 bits of the address, the ... DRAM then "fetches" the ... -
Knight Lore disassemblyHi, Not quite sure if this belongs here or in "Games" but figured it's more likely that developers would be interested. I've just released the …
... The lowest address used in RAM is $5BA0. Immediately following the last byte of ... code at $D8F3 is the ... up tables built in the start-up code for ... better off just rebuilding the source (when I release ... -
Knight Lore disassemblyHi, Not quite sure if this belongs here or in "Games" but figured it's more likely that developers would be interested. I've just released the …
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The lowest address used in RAM is $5BA0. Immediately following the last byte of code ... at $D8F3 is the ... rotational keyboard controls were top of the list (of course you can use ... -
2x2 tile to attribute blocksHow do you go about converting a 2x2 tile to 16 x 16 attributes? Heres an example of the tile data I'm wanting to enlarge. [code] defb 255, 25…
... /> RET
DrawAttrGraphic2 ; used for drawing 16 ATTR bytes ... /> DJNZ drawstar1 ; do all 8 bits of the byte. 8 squares
INC ...
