Hi all, Just a quick note to say I've uploaded a set of information to enable building and installation in M100 of the 1x2x clock doubler board Version 4.6. Gerbers, images, schematic, Eagle design files, BOM, how-tos. https://bitchin100.com/wiki/index.php?title=5MHZ_upgrade_for_Model_T Interested folks can give it a try and let me know what needs improvement. Next up - Olivetti M10, Tandy 200, Tandy 102, PC-8201 in more or less that order.
cheers Steve On Sat, Nov 18, 2023 at 10:54 AM Stephen Adolph <twospru...@gmail.com> 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 > > 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 > > > > >
