[cctalk] Re: 7485 chip history??? (Solid State Music SB-1)
For anyone that might be interested, I was able to get some 74L85s. After installing them (and chasing down a misbehaving 7400) I was rewarded with a fully functional SSM SB-1. Bill -Original Message- From: Chuck Guzis via cctalk [mailto:cctalk@classiccmp.org] Sent: Thursday, September 22, 2022 3:22 PM To: cctalk@classiccmp.org Cc: Chuck Guzis Subject: [cctalk] Re: 7485 chip history??? (Solid State Music SB-1) On 9/22/22 09:55, John Robertson via cctalk wrote: > On 2022/09/19 9:51 p.m., ben via cctalk wrote: >> On 2022-09-19 10:18 p.m., Tom Hunter via cctalk wrote: >>> There are a few US based Ebay sellers of the 74L85. >>> >>> Tom >> But most ebay sellers, from the USA seem to sell a item for $6.00 and >> $75 shipping to Canada. China $2 and $3 shipping. With Covid all >> shipping is several weeks. >> Ben. >> > How many do you need? I have one or more of 74LS85, 74C85, 74HC85, and > 7485... The ICs that you've listed as having (74LS85, 74C85, 74HC85, and 7485) aren't what the OP needs. The 74L85 is a different animal with a different pinout from the chips you've listed. --Chuck -- This email has been checked for viruses by Avast antivirus software. www.avast.com
[cctalk] Re: 7485 chip history??? (Solid State Music SB-1)
On 9/22/22 09:55, John Robertson via cctalk wrote: > On 2022/09/19 9:51 p.m., ben via cctalk wrote: >> On 2022-09-19 10:18 p.m., Tom Hunter via cctalk wrote: >>> There are a few US based Ebay sellers of the 74L85. >>> >>> Tom >> But most ebay sellers, from the USA seem to sell a item for $6.00 and >> $75 shipping to Canada. China $2 and $3 shipping. With Covid all >> shipping is several weeks. >> Ben. >> > How many do you need? I have one or more of 74LS85, 74C85, 74HC85, and > 7485... The ICs that you've listed as having (74LS85, 74C85, 74HC85, and 7485) aren't what the OP needs. The 74L85 is a different animal with a different pinout from the chips you've listed. --Chuck
[cctalk] Re: 7485 chip history??? (Solid State Music SB-1)
On 2022/09/19 9:51 p.m., ben via cctalk wrote: On 2022-09-19 10:18 p.m., Tom Hunter via cctalk wrote: There are a few US based Ebay sellers of the 74L85. Tom But most ebay sellers, from the USA seem to sell a item for $6.00 and $75 shipping to Canada. China $2 and $3 shipping. With Covid all shipping is several weeks. Ben. How many do you need? I have one or more of 74LS85, 74C85, 74HC85, and 7485... Email me directly with which version you prefer. These are all NOS parts, not pulls. John :-#)# -- John's Jukes Ltd. 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 Call (604)872-5757 (Pinballs, Jukes, Video Games) flippers.com "Old pinballers never die, they just flip out"
[cctalk] Re: 7485 chip history??? (Solid State Music SB-1)
Ben, I buy lots of stuff from eBay US sellers and most are willing to check/fix shipping costs. If not then I use a drop-box service where the item is shipped to Oregon, and then reshipped to me for a not too horrible cost. Lastly, I’ll be back at my shop in Burnaby in a couple of days and can check my inventory of TTL chips - might well have your 74L85, and postage is pretty cheap within Canada. I’ll try not to hose you too badly on the chip cost! John :-#)# > On Sep 20, 2022, at 5:52 AM, ben via cctalk wrote: > > On 2022-09-19 10:18 p.m., Tom Hunter via cctalk wrote: >> There are a few US based Ebay sellers of the 74L85. >> Tom > But most ebay sellers, from the USA seem to sell a item for $6.00 and > $75 shipping to Canada. China $2 and $3 shipping. With Covid all shipping is > several weeks. > Ben. > > >
[cctalk] Re: 7485 chip history??? (Solid State Music SB-1)
And I thought shipping to Australia (opposite side of the planet) was expensive. Shipping from the US to Canada should be dirt cheap as mail can move via trains not air freight. $75 shipping for an IC is crazy no matter what the destination is (except maybe Mars). Tom On Tue, Sep 20, 2022 at 12:51 PM ben via cctalk wrote: > On 2022-09-19 10:18 p.m., Tom Hunter via cctalk wrote: > > There are a few US based Ebay sellers of the 74L85. > > > > Tom > But most ebay sellers, from the USA seem to sell a item for $6.00 and > $75 shipping to Canada. China $2 and $3 shipping. With Covid all > shipping is several weeks. > Ben. > > > >
[cctalk] Re: 7485 chip history??? (Solid State Music SB-1)
On 2022-09-19 10:18 p.m., Tom Hunter via cctalk wrote: There are a few US based Ebay sellers of the 74L85. Tom But most ebay sellers, from the USA seem to sell a item for $6.00 and $75 shipping to Canada. China $2 and $3 shipping. With Covid all shipping is several weeks. Ben.
[cctalk] Re: 7485 chip history??? (Solid State Music SB-1)
There are a few US based Ebay sellers of the 74L85. Tom On Tue, Sep 20, 2022 at 10:50 AM ben via cctalk wrote: > On 2022-09-19 8:07 p.m., William Sudbrink via cctalk wrote: > > Hi, > > > > I recently acquired a Solid State Music SB-1 from which all the chips had > > been removed. I've reinstalled all of the chips (I located an SSM2000) > and > > I've been trying to figure out why this board crashes my computers. The > > conclusion that I've come to is rather astounding. The board specifies > two > > 74ls85 4 bit binary comparator chips to perform address decoding. The > > designers of this board seem to have had incorrect pinouts for it. Every > > source that I can find specifies: > > > >B3116 VCC > > A > A=B (in)3 14 B2 > > A>B (in)4 13 A2 > > A>B (out) 5 12 A1 > > A=B (out) 6 11 B1 > > A > GND 8 9 B0 > > > > The 7485s that I was able to get have this pinout. BUT! The SB-1 is > > designed as: > > > >B2 1 16 VCC > >A2 2 15 A3 > > A=B (out) 3 14 B3 > > A>B (in)4 13 A>B (out) > > A > A=B (in)6 11 B0 > >A1 7 10 A0 > >GND8 9 B1 > > > > I Ohm'd out the board to verify this and it matches the schematic here: > > https://wiki.theretrowagon.com/wiki/Solid_State_Music_SB1 > > What the heck??? Did the pinout of the 7485 just arbitrarily change at > some > > point? Was this some competition between manufacturers? Is there any > way > > to get the "right" 7485? > > > They are both right. > 7485,74LS85,74S85 top pin out. > 74L85 the bottom pin out. SB-1 > TTL data book 1985. > > > > Thanks, > > Bill > > > > > I suspect they used the L for low input loading > for the address bus. The 74C85 (fairchild ) would be the sane > substitute for the 74L85. > Ben. > >
[cctalk] Re: 7485 chip history??? (Solid State Music SB-1)
On 9/19/22 19:07, William Sudbrink via cctalk wrote: Have a look at the 74L85 (not LS). it's one of those oddities that some of the "L" 74 series logic have different pinouts than the standard/LS/S/H/F/ One notable aspect is that it's possible to wire-OR the L series outputs--something that you don't want to do with the others. --Chuck > Hi, > > I recently acquired a Solid State Music SB-1 from which all the chips had > been removed. I've reinstalled all of the chips (I located an SSM2000) and > I've been trying to figure out why this board crashes my computers. The > conclusion that I've come to is rather astounding. The board specifies two > 74ls85 4 bit binary comparator chips to perform address decoding. The > designers of this board seem to have had incorrect pinouts for it. Every > source that I can find specifies: > > B3116 VCC > A A=B (in)3 14 B2 > A>B (in)4 13 A2 > A>B (out) 5 12 A1 > A=B (out) 6 11 B1 > A GND 8 9 B0 > > The 7485s that I was able to get have this pinout. BUT! The SB-1 is > designed as: > > B2 1 16 VCC > A2 2 15 A3 > A=B (out) 3 14 B3 > A>B (in)4 13 A>B (out) > A A=B (in)6 11 B0 > A1 7 10 A0 > GND8 9 B1 > > I Ohm'd out the board to verify this and it matches the schematic here: > https://wiki.theretrowagon.com/wiki/Solid_State_Music_SB1 > What the heck??? Did the pinout of the 7485 just arbitrarily change at some > point? Was this some competition between manufacturers? Is there any way > to get the "right" 7485? > > > > Thanks, > Bill > > > > > -- --Chuck Sent from my digital computer
[cctalk] Re: 7485 chip history??? (Solid State Music SB-1)
On 2022-09-19 8:07 p.m., William Sudbrink via cctalk wrote: Hi, I recently acquired a Solid State Music SB-1 from which all the chips had been removed. I've reinstalled all of the chips (I located an SSM2000) and I've been trying to figure out why this board crashes my computers. The conclusion that I've come to is rather astounding. The board specifies two 74ls85 4 bit binary comparator chips to perform address decoding. The designers of this board seem to have had incorrect pinouts for it. Every source that I can find specifies: B3116 VCC AB (in)4 13 A2 A>B (out) 5 12 A1 A=B (out) 6 11 B1 AB (in)4 13 A>B (out) Ahttps://wiki.theretrowagon.com/wiki/Solid_State_Music_SB1 What the heck??? Did the pinout of the 7485 just arbitrarily change at some point? Was this some competition between manufacturers? Is there any way to get the "right" 7485? They are both right. 7485,74LS85,74S85 top pin out. 74L85 the bottom pin out. SB-1 TTL data book 1985. Thanks, Bill I suspect they used the L for low input loading for the address bus. The 74C85 (fairchild ) would be the sane substitute for the 74L85. Ben.
