Path: news.weeg.uiowa.edu!news.uiowa.edu!hobbes.physics.uiowa.edu!math.ohio-state.edu!sdd.hp.com!elroy.jpl.nasa.gov!usc!news.service.uci.edu!nntpsrv From: pho@vmsa.oac.uci.edu Subject: Re: 16 MHz 64k Zip Benchmarks Nntp-Posting-Host: vmsa.oac.uci.edu Message-ID: <2C60EB21.15988@news.service.uci.edu> Newsgroups: comp.sys.apple2 Organization: University of California, Irvine Lines: 98 Date: 5 Aug 93 11:12:33 GMT Posted for Long Hoang. Frank, Here are some more info that you might find useful for the TWGS/Zip FAQ. NoiseTracker v1.0/1.1 reports 11.271 MHz for a 16 MHz 64k Zip GSX. I believe someone mentioned 10.33 MHz for a 15 MHz TWGS. Correct me if I'm wrong. 6. Where can I buy crystal oscillators? for Zip you need: 1/2 TTL or full TTL? Speak up Zip owners! The Zip can use three types of crystals including the common 4-pin full TTL crystal oscillator, 4-pin 1/2 TTL crystal oscillator (also used on TWGS) and 2-pin crystal (little metal canister about 1/4 the size of 1/2 TTL). To be able to use a 2-pin crystal, your Zip must have a resistor at R1 and capacitors at C13 and C14. I've found these three parts to be missing from current Zips. No big loss since 2-pin crystals are less common and are only available up to a certain frequency. I have the values of those parts written down somewhere and will post them when I find them. For experimenting with different frequencies it makes it easier if you install a socket for the crystal oscillator. It's also a good idea to secure it down with one of those zip tie bands. Only 6 of the 14 pins are used (picture A). The ground (GND) pins 1, 4 and 7 are connected together. The power pins 11 and 14 are connected together. Full TTL crystal oscillators use pins 1, 7, 8 and 14 (refer to picture B). 1/2 TTL crystal oscillators use the bottom four pins (4, 7, 8 and 14; picture C). Make sure it's oriented correctly with the corner (usually with a dot printed next to it) at about 11 o'clock. *WARNING* The crystal oscillator will be damaged if installed incorrectly. _______ GND 1 o \/ o 14 POWER 1 |o \ 14 NC x x NC | | NC x x NC | FULL | ______ GND 4 o o 11 POWER | TTL | 4 |o \ 14 NC x x NC | | | 1/2 | NC x x NC | | | TTL | GND 7 o o 8 CLOCK 7 \______/ 8 7 \_____/ 8 (A) (B) (C) x - no connection (NC) 7. What speed of static cache RAMs do I need? for Zip you need: speak up Zip owners. I've found Japanese and American static rams to work the best (20 ns in tag and 25 ns in data). The Zip can use narrow (.3 mil) or wide (.6 mil) static rams. It all depends on the sockets that are installed on your Zip. With a little modification you can make a Zip with wide sockets accept both wide and skinny static rams. Ground yourself then carefully pry out the static rams. Look at the socket and you will notice two or three horizontal bars holding both sides of the socket together (picture D). Carefully cut those out. This will expose a column of holes where you will solder in half of a socket. Refer to picture E, position skinny (.3 mil) static rams over the left and center columns and wide static rams over outer most columns and making sure the notch on the static ram is facing 12 o'clock. *WARNING* Plug the static rams in wrong and you will destroy them. CUT ___ ___________ Skinny (.3 mil) | | | | ____ ____ _ _ _ |o __V__ o| |o| |o| |o| |o| o |o| |o| |o| |o| |o| o |o| |o| |o| |o| |o| o |o| |o| |o| |o| |o| o |o| |o| |o| |o| |o| o |o| |o| |o| |o| |o|__o__|o| |o| |o| |o| |o _____ o| |o| |o| |o| |o| o |o| |o| |o| |o| |o| o |o| |o| |o| |o| |o| o |o| |o| |o| |o| |o| o |o| |o| |o| |o| |o|__o__|o| |o| |o| |o| |o _____ o| |o| |o| |o| |_______|___ Wide (.6 mil) (D) (E) 12. Is it true that Zip can only go about 12.5 mHz? Only if you don't know how to make it run faster. With a little bit of work it can run up to 16 MHz just fine and possibly even faster.