I jumped the gun a bit, needed to redo the boards and change the circuit. On Sunday, November 19, 2023, Brian K. White <b.kenyo...@gmail.com> wrote:
> None of the file links work, but I'm sure it *will* be awesome. > Sounds super. > > On 11/18/23 10:54, Stephen Adolph wrote: > >> Hi everyone, >> >> I've been working towards finishing off my project for increasing the >> speed of the Model T laptops. The idea is to create a (relatively) easy to >> make and install solution that allows the user to switch the clock rate >> from 2.5 MHz to 5 MHz. >> This is really nice on the 40x8 LCD machines. >> >> The universal software command to switch clock rate is >> OUT 85,1 for 2x mode and >> OUT 85,0 for 1x mode. >> >> Of course the Model T is not designed for this, but in my experience so >> far, it seems reliable. I really like the upgrade and plan to install in >> all my laptops. Being able to operate in nominal clock mode is of course >> very useful because you may find some software to be incompatible. >> >> Models I have upgraded to date: >> * M100 (NA, early variant, not UK) >> * T102 >> * T200 >> * NEC PC-8201/8201a >> * Olivetti M10 >> >> I am publishing all the information needed to DIY this upgrade. I don't >> have any plans to make these upgrades. Consider this upgrade only if you >> are comfortable with soldering surface mount parts, and with making minor >> modifications to your laptop. >> >> Upgrades that are done and in the process of documentation are M100, >> T200, NEC. Upgrades that need a new PCB design still are T102 and M10. >> All information will be at this site: >> >> https://bitchin100.com/wiki/index.php?title=5MHZ_upgrade_for_Model_T < >> https://bitchin100.com/wiki/index.php?title=5MHZ_upgrade_for_Model_T> >> >> I am publishing >> * PCB designs for the clock doubler board (there are a few variants) >> * schematic >> * bill of materials for parts you need >> * documentation for building the clock doubler >> * installation documentation per laptop >> >> Things I have discovered while developing this; >> 1. Power consumption goes up by about 20% when you run at 2x clock. >> 2. Depending on the speed of your SRAM, you may need to implement a >> modification to speed that up. Each model has a specific mod you need. >> 3. In M100 with the custom socket pinout, in most cases you need to >> upgrade your Main ROM to something faster. This usually involves an >> adapter board and an EPROM. >> 4. In the Tandy 200, one must slow down the machine temporarily to >> access the RTC. There is a specific change for that. >> >> Anyhow, as I complete a particular laptop, I'll post the needed files. >> >> Hopefully this will be of some interest for those inclined to play around >> with hardware. I have no problem if anyone wants to take the design and >> improve it or change it. >> >> Feel free to contact me directly with questions. >> >> cheers >> Steve >> >> >> >> >> > -- > bkw > >
