50g stack font

[rprosperi]

(07-24-2019 02:30 PM)DavidM Wrote:  

(07-24-2019 12:48 PM)rprosperi Wrote:  @DavidM - Though the contrast on all my 50g's are fine and I hope to never need this, I am curious where you were able to find such details? And thanks for posting this interesting reply.

This topic came up in another thread some time ago... this one I believe. On page 4 or so of that thread a discussion started about setting the contrast programmatically. I had run across some information in the comp.sys.hp48 archives that led me to believe that those memory locations no longer worked for contrast, but then subsequently discovered that method was still valid as of some unknown update in the firmware.

IIRC, there's also some references to the addresses in various memory map documents available from hpcalc.org.

I guess I'm either unlucky or overly picky (more likely) about the contrast settings in my calculators, because none of my 48-50 calculators seem to default to optimal settings (I believe 14 is the firmware default setting). While I'm fortunate to have acquired a black screen 48GX that appears to have had very little use by the original owner, its display is almost unreadable at the default contrast setting (which might explain why it has had such little use). Adjusting the contrast on that unit is absolutely required any time a warm (or cold) -start has occurred. I just wish there was a reliable way I could identify that unit programmatically so that my standard routine could automatically determine it was running on that machine. The ARM systems have a "soft" serial number that can be referenced, but the 48-series doesn't.

Thanks very much. Of course the answer to where the incredibly gory details come from is Hrast! Between Hrast, Joe Horn and John Meyer, I think they account for about 95% of the 'obscure detail' questions that have ever been answered.

All of my 50g's seem excellent from reset, but it has been a lonnng time since some were reset, so maybe my memory is off. For 48's some of my blue-LCD GX's and one of my SX have poor power-on contrast, but all of my black-LCD GX's are excellent. Maybe I'm just lucky.

For folks that want code to adjust the contrast, the linked thread includes a program from Hrast which can be easily decompiled/disassembled, and he has allowed community use.