Started by andreas_g, February 27, 2023, 07:14:45 AM
Quote from: andreas_g on February 27, 2023, 07:14:45 AMFinally I read somewhere, that later versions of the non-Turbo NeXTstations had a different memory layout and supported up to 128 MB RAM. Unfortunately I don't remember where I read that.
Quote from: andreas_g on February 27, 2023, 07:14:45 AMHello all,it turned out recently, that NeXTStep 2.0 has the ability to run on a never released prototype of the NeXTstation Color. That prototype obviously had a different memory layout, where the VRAM is located at address 0x06000000 instead of 0x2c000000. Furthermore the headers that come with NeXTStep indicate that there are non-Turbo NeXTstations and NeXTcubes with a revised main board (rev. 1) that utilized the new clock chip (MCCS1850). Finally I read somewhere, that later versions of the non-Turbo NeXTstations had a different memory layout and supported up to 128 MB RAM. Unfortunately I don't remember where I read that.Now I'd like to find out here, which of these really existed, what other prototypes or variations are known and what special characteristics they had.
Quote from: andreas_g on February 28, 2023, 12:52:23 AMThank you for these interesting details! Does someone in here own a non-Turbo NeXTstation or NeXTcube with new clock chip? It would be interesting what it reports for SCR1 and SCR2 (ROM Monitor > s).
Quote from: Nitro on February 28, 2023, 08:21:41 PMHere's a non-Turbo 25MHz NeXTstation with the new chip set.
Quote from: Nitro on March 01, 2023, 01:11:06 AMOops, my bad. I misunderstood what you were looking for. I'll see if I have any non-Turbos with the new clock chip.
Quote from: Nitro on March 05, 2023, 03:24:14 AMI don't have any boards with clock chips specifically marked MCCS1850. I do have one of the early mono non-turbo NeXTstation boards with a MC68HC68T1 chip, different board layout and a socketed engineering sample CPU. The other non-turbo mono NeXTstations are the newer boards with soldered CPUs and XCCS1850DW clock chips. I don't have any prototypes. You might ask @eagle as I believe he has a prototype cube.
Quote from: Nitro on March 05, 2023, 06:08:30 AMI can do that, give me a minute to get a monitor set up. Yes, I believe Motorola used the X prefix for chips until they were qualified, then changed them to M. If you look closely at the early board the DSP56001 chip is marked XSP56001. Also, the engineering sample CPU is marked PC68040RC-A.