04 June 2012, 10:53 | #1 |
Targ Explorer
|
Speedy. The variable speed accellerator.
Has anyone ever tried one of these variable speed oscillators on an amiga accellerator?
http://www.micromac.com/products/speedy.html |
04 June 2012, 11:53 | #2 |
Registered User
Join Date: Apr 2011
Location: birmingham
Age: 55
Posts: 2,827
|
i was looking for one of these a few months back,does anyone know the frequency range of one of these?
it would have to work(adjustable) between 50-120mhz in my case. and what are the incraments between frequencys i wonder. |
04 June 2012, 11:59 | #3 |
Targ Explorer
|
Looking at the table on the link, 30 - 125mhz is the range. It also seems to be fine enough to deliver speeds which involve single unit changes.
Availability is my big question. The link is old... |
04 June 2012, 12:03 | #4 |
Registered User
Join Date: Apr 2011
Location: birmingham
Age: 55
Posts: 2,827
|
yeah thats what im worried about,the link is pretty old.
it should work as it replaces the can oscillator,and it is 5 volt and ttl by the look of it. |
04 June 2012, 12:42 | #5 |
Registered User
Join Date: Jan 2008
Location: United Kingdom
Age: 46
Posts: 735
|
One of these devices from Linear Technology would work,
http://www.linear.com/product/LTC6905 and you can purchase it from Farnell. A small PCB and it could fit 8/14 pin DIL sockets. Ian |
04 June 2012, 13:00 | #6 |
Registered User
Join Date: Apr 2011
Location: birmingham
Age: 55
Posts: 2,827
|
looks interesting i might give one of these a go stedy.
|
06 June 2012, 22:59 | #7 |
Registered User
Join Date: Jan 2008
Location: United Kingdom
Age: 46
Posts: 735
|
Hi,
Just checked the workshop stores, I have a couple of LTC6907 (40KHz to 4 MHz), bought for another project I will test shortly. The 1-2% accuracy does concern me a little but for a CPU it should be OK. I typically use around 0.0035% accuracy crystals. Will report back with test results. Ian |
06 June 2012, 23:31 | #8 |
Registered User
Join Date: Apr 2011
Location: birmingham
Age: 55
Posts: 2,827
|
hi stedy,do you think it would be better to run a LTC6905 on 3.3 volts rather than 5 volts.
i dont know how it will fair between 50 and 110mhz. |
18 June 2012, 20:53 | #9 |
Registered User
Join Date: Jan 2008
Location: United Kingdom
Age: 46
Posts: 735
|
Hi,
I tested the LTC6907 device I had and was pleased with the results. Initial frequency accuracy was within tolerance (0.7% compared to a potential 1%) and waveform shape/symmetry was good. Would like to try it with some 0.1% resistors, when I buy some. @roy bates The LTC6905 can use 3.3V or 5V, which is great. The 68060 is 3.3V and I would expect the clock source to also be 3.3V LVTTL. My only concern with using 3.3V with a 5V part, is if the CPU or CPLD has HCMOS inputs, so requires 3.33V minimum (66% of 5V) for a logic 1. Would need to check all potential devices. Using the LTC6905 is easy enough though. Could easily make some adaptors, if there was the demand. Ian |
18 June 2012, 21:33 | #10 |
Registered User
Join Date: Apr 2011
Location: birmingham
Age: 55
Posts: 2,827
|
it shouldent be a problem really, all 040 and 060 cards oscilators on amigas are 5 volts ,i was just wondering if it could be run on 3.33 volts and still be usable.
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
Thread Tools | |
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Join variable and string in scripts. | olesio | support.Apps | 3 | 31 January 2013 11:44 |
NTSC variable-length scanlines | TheDarkCoder | Coders. Asm / Hardware | 3 | 23 November 2011 15:51 |
Shoot the Speedy One... | JonSick | request.Old Rare Games | 0 | 16 September 2010 12:14 |
What accellerator do I need ? | Kakaboy | Hardware mods | 13 | 23 March 2010 04:33 |
Variable Master Clock | wiltshireguyuk | request.UAE Wishlist | 0 | 13 December 2004 16:40 |
|
|