I made a debugger that draws the state machine of the program

Post by jacquesm » Thu, Jan 08, 2015, 6:39 PM UTC

jloughry wrote: post #46

jacquesm wrote: post #3

That is absolutely awesome. I used to have something like this: a pair of very fast dacs hooked up to the 16 address lines of my computer and another dac hooked up to the databus. It allowed me to look straight into the memory of the machine as the processor was accessing it, quite a powerful tool. Yours is nicer though (and with todays memory size I'd hate to think about the quantity of data that passes in a split s…

> a pair of very fast dacs hooked up to the 16 address lines of my computer and another dac hooked up to the databus. Here's an article about it, with photos [1]. I remember reading it in BYTE, years ago. https://archive.org/stream/byte-magazine-1978-02/1978_02_BYT... Edit: I'll bet it's no longer possible to do this on modern CPUs; either the memory busses are inaccessible (SoC) or so highly optimised (DDR4) that it…

Besides that you'd have a serious problem getting a DAC that is fast enough and with enough bits.

Post by mncolinlee » Thu, Jan 08, 2015, 7:26 PM UTC

arethuza wrote: post #11

jacquesm wrote: post #3

That is absolutely awesome. I used to have something like this: a pair of very fast dacs hooked up to the 16 address lines of my computer and another dac hooked up to the databus. It allowed me to look straight into the memory of the machine as the processor was accessing it, quite a powerful tool. Yours is nicer though (and with todays memory size I'd hate to think about the quantity of data that passes in a split s…

That reminds me of the old story of people having a audio speaker connected to the address but of their mainframe so they could detect error conditions by the sounds being made.

The Radio Shack TRS-80 Model 1 was legendary for the amount of radio interference it caused. I used this at age 7 along with my older brother to add sounds and victory music to pinball games. You could tune the FM radio to a harmonic of the frequency of the processor. Then you constructed loops with short delays to alter the frequency of the sound. You'd hear all kinds of processing garbage during the game loop, but the sounds came out fine.

Re: I made a debugger that draws the state machine of the program

Re: I made a debugger that draws the state machine of the program