We had already retired ours, and had replaced it with a much discounted TIA, with a better keyboard. I can use basically anything, but with a bad keyboard.
The engineering miracle of the Sinclair ZX Spectrum
I am not going to type for hours…. It was an exciting time, just not for poor machines. Who wanted Manic Miner? Thankfully my uncle was far less strict, and my cousin had a Spectrum, and we spent so many saturdays listening to its chirps and playing those wonderful games… To tell the truth, they have aged very badly, as an evening with an emulator will reveal, unlike many NES games which are still fun to play and cute to look at, but at the time they felt to me like diving into the future.
But my dad deemed it as a toy which it was, which is why I wanted it , and it was far beyond my reach. The Commodore Colt? There was choice! It felt like there was an endless supply of new machines coming out each month, and you could only imagine how fantastic this was going to be. In retrospect there was 2 3 if being generous CPUs in use, and just a few gfx and sound chips being combined. More saddening is that you had a matching choice of magazines, so much larger than today even if excluding machine specific ones.
Still have a Timex with original box somewhere on the attic. Exactly my thoughts! Retro Asylum 5 hrs. Robert Francis June 23 at AM.
ZX Spectrum - Issue with RS (Serial Port) - Stack Overflow
If you attempt to close a channel which is already closed on an unexpanded Spectrum then the machine might crash due to two bugs in the ROM. The unexpanded Spectrum supports four channels: "K" the keyboard channel, "S" the screen channel, "P" the printer channel, and "R" an internal channel used by the Spectrum to send data to the edit buffer. In practice the only channel that has both input and output of these is the keyboard channel. When the Spectrum is first powered up the following streams are opened automatically: 0: "K", 1: "K", 2: "S", 3: "P".
See a Problem?
It is possible to redefine the standard channels, thus OPEN 2, "P" will cause output normally sent to the screen to be redirected to the printer. Device Independence The most important advantage of using streams is in the writing of device independent programs. Say that you wish to give the user the option of having all output go to either the screen or to the printer.
Further, it is an easy matter to add even further output devices if they become an option later in the programs development. LIST s will send a copy of the program to stream s; e.
Memory Formats Knowing about the actual layout of the stream records in memory is useful if you want to add your own hardware devices to the Spectrum, or if you which to make you own specialized streams. Each channel record has the following format: two-byte address of the output routine, two-byte address of the input routine, one-byte channel code letter.
The output routine must accept Spectrum character codes passed to it in the A register. The input routine must return data in the form of Spectrum character codes, and signal that data is available by setting the carry flag. If no data is available then this is indicated be resetting both the carry and zero flags. Stubs should be provided if a channel does not support either input or output e. Either of them could be an ordinary number instead, in which case the shadow ROM will not be paged in and the word at offset 5 or 7 as appropriate could contain any data.
Data about which streams are associated with which channels is in a byte area of memory starting at STRMS.
This accounts for 32 bytes of the 38 - the remaining 6 bytes are for three hidden streams , , used internally by BASIC. A zero entry in the table indicates a stream not open.
It is easiest to modify the existing "P" channel record. This channel has an output routine at and an input routine at generates error report 'J'. A new entry is created in the STRMS table which points to the address of the second byte of new channel data. The stream number can be from -3 to 15, but it is best to stick to the range 4 to 15 and not modify the system streams -3 to -1 or the standard streams 0 to 3.
However, the EAR and MIC sockets are connected only by resistors, so activating one activates the other; the EAR is generally used for output as it produces a louder sound. The upper two bits are unused. If Port 0xfe is read from, the highest eight address lines are important too. If more than one address line is made low, the result is the logical AND of all single inputs, so a zero in a bit means that at least one of the appropriate keys is pressed.
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A final remark about the keyboard. It is connected in a matrix-like fashion, with 8 rows of 5 columns, as is obvious from the above remarks. Any two keys pressed simultaneously can be uniquely decoded by reading from the IN ports. However, if more than two keys are pressed decoding may not be uniquely possible. Many of the sections contain obsolete information or are completely out of date.
Confirmation of the shilling that went on from certain individuals during this absolute scandal.
What a disgrace! Well it seems justice has prevailed for once and no surprises there to be honest what a ridiculous bit of behaviour! Please sign the change.