Please find below a suggested method for sourcing the parts for a small run of the device:

;----------------
; Integrated Circuits
;----------------

| U1         	MC6800		https://www.aliexpress.com/item/1005004479143065.html
      
| U2         	2716		*** AT28C256 ALREADY ON HAND
        
| U3,U4		6116		*** UT6264CPC-70LL ALREADY ON HAND
       
| U5,U6         74LS367		https://www.ebay.com.au/itm/392646329463
     
| U7         	CD4014		https://www.aliexpress.com/item/1005006007339909.html
      
| U8         	MC6875		https://www.aliexpress.com/item/4000045848422.html
     
| U9         	MC6821		*** MOS6522 ALREADY ON HAND
     
| U10        	74LS10		https://www.ebay.com.au/itm/124270171410
      
| U11,U17	74LS04		https://www.ebay.com.au/itm/334703255973
      
| U12        	74LS08		https://www.ebay.com.au/itm/234861194857
      
| U13        	CD4040		https://www.aliexpress.com/item/1005006389797996.html
      
| U14,U15	74LS93		https://www.ebay.com.au/itm/234860939045
           
| U16        	74LS20		https://www.ebay.com.au/itm/392646331384
      
| U18        	74LS11		https://www.ebay.com.au/itm/234868819629
      
| U19        	74LS123		https://www.aliexpress.com/item/1005005071495170.html
     
| U20        	7440		https://www.aliexpress.com/item/1005005805134654.html
        
| U21        	74LS74		https://www.ebay.com.au/itm/234862799526
      
| U22        	74121		*** ALREADY ON HAND
       
| U23        	LM741		https://www.aliexpress.com/item/1005006103890733.html
       
| U24        	NE566		https://www.aliexpress.com/item/1005006022531540.html
       
| U25        	74LS138		https://www.ebay.com.au/itm/184350879253
     
| U26        	LM2576-5.0	https://www.aliexpress.com/item/1005005877381901.html
  
| U27        	LT1054		https://www.aliexpress.com/item/1005005658624513.html