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1

Writing games those days was a long process, full of write - save - compile - run - crash - load - edit cycles. It was very frustrating, especially in the case you had only the tape recorder. Microdrives or floppy shorts the save / load time to minimum... So basically: yes, you can develop the game on the ZX Spectrum itself. The assembler itself takes some ...


9

Considering how much of a rush job Locomotive BASIC was, it's remarkably good. But it's not perfect. Sinclair BASIC has one powerful keyword that Locomotive BASIC lacks: VAL. Sure, Locomotive BASIC has a VAL() function, but Sinclair's one is a function evaluator: 10 FOR X=-5 TO 5 20 PRINT X,VAL ("X * X") 30 NEXT X This would fail on an Amstrad CPC, but on ...


20

Was Locomotive BASIC significantly better than Sinclair BASIC? TL;DR: Oh, yes, it was! I'm aware that both Basics were more advanced than the C64 Microsoft implementation, Comparison of C64 BASIC to other BASICs of the same time is never in favour for the C64, as it's a quick port of the original 1977 PET Version. but neither [Locomotive BASIC, ...


22

The big improvement to the language in Locomotive BASIC, compared to Sinclair BASIC (and many other BASICs), was the addition of timer support: AFTER 50,0 GOSUB 320 would call the subroutine at line 320 after a second, and EVERY 500,0 GOSUB 320 would call the subroutine every ten seconds. In both cases, the first value is the interval in fiftieths of a ...


4

In the Spectrum lexicon, a t-state is just a "time state" — a single cycle of the ~3.5Mhz clock. For implied evidence of that, see e.g. this document of 128K ZX Spectrum Technical Information, which states ... there are 70908 T states per frame, and the '50 Hz' interrupt occurs at 50.01 Hz. 70908 t-states per frame * 50.01 Hz = 3.546 million t-states ...


7

Check this Spectrum tape interface: Pulses A 'pulse' here is either a mark or a space, so 2 pulses makes a complete square wave cycle. Pilot tone: before each block is a sequence of 8063 (header) or 3223 (data) pulses, each of length 2168 T-states. Sync pulses: the pilot tone is followed by two sync pulses of 667 and 735 T-states resp....


6

Those variable amplitudes looks like electronics problem like failing caps somewhere along the way (recording/playback) or unshielded too long cables or partial remagnetization or even HW bug (some recorders like ELTA have a bug in writing head circuitry that corrupted tapes a bit each time it was played ...) the correct output should be a rectangular ...


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